Ursus followed the path which led to the chamber where the Essence of Gluttony was located. As he moved on he saw multiple bodies of the guards disguised as librarians littering the floor.

'They most likely died trying to stop Yuusha from entering the chamber of Gluttony, however how did they die so quickly?'

Ursus inspected some of the bodies, bring his face in closer.
The guards were dealt with a blunt weapon and a blade, a conclusion deduced by observing the external damages on the bodies he had seen so far. A piece of the stone wall had it's moss charred, most likely from the resistance of the palace guards, aside that there were also traces of magic, however all the weapons of the guards were still inside their scabbards. It was very unlikely that Yuusha even bothered to put them back in after they pulled them out. So that's why Ursus thought.

'They were taken by surprise'

Most of them had been killed before they themselves had even noticed. It was obvious from the expressions of their faces which said, that even they didn't know they had left this world.
That explains how they died so easily, however something else still bugged Ursus.

'That still doesn't explain how some of their armour looked like it had been trampled on by a minotaur.' Ursus thought.

Yuusha had skin so pale that she looked like she had an illness, He could see how thin her limbs were even though they were hidden with sleeves, and not only that but Yuusha was a woman to boot. Ursus couldn't fathom as to how a girl with such physical features could even cause such injuries. Ursus could tell that she didn't use any magic and that was because...

"She doesn't have any mana."

Humans who couldn't use mana relied on petty tricks and scheme to defeat their opponents, that was what Ursus believed.
It would have been understandable if the guard's necks were cleanly slit, but a human causing such wounds without the use of mana was something incomprehensible to Ursus.
Then there was just one conclusion left.

'I don't know.'

Ursus didn't know, so that's why he decided to adapt at whatever Yuusha throws at him because that is how Ursus did things up until now, and it was the reason he got into the Imperial Magic Knight Order at such a young age.
Ursus ran, following the bloody trail not delaying his divine retribution any further.
To deliver justice and to protect the Kingdom.
That is the duty of Ursus, or so he believed.

*clank*
*clank*
*clank*
*clank*
*clank*
*clank*

Ursus' metal greaves made a loud sound every time it made contact with the stone floor, Ursus had never seen this part of the castle before however he couldn't afford to slow down, and eventually it wasn't just the sound of his metal greaves hitting the floor that could be heard.

*munch*

Ursus heard a munching sound, it echoed throughout the passage and sent a chill upon Ursus' spine, it was a sound that sounded like meat was being devoured.

*crack*

Then there was the sound of bone cracking, but the sound didn't make it seem like it belonged to anything flimsy like a chicken bone. It sounded even bigger and due to Ursus' anxiousness he sped up.

And after a hard right turn there he saw it.
It was Yuusha, albeit she was covered in black filth, but as if he could peer beneath it, his instincts told him that it was without a doubt Yuusha.
Her red eyes glowed as she brought the corpse of a palace guard's arm and then...

She chewed on it's bare flesh.

This action which Ursus saw only made one thing flow through Ursus' mind.

Anger.

Ursus already held enough hate, even though the chance was little, he sincerely hoped that maybe, just maybe Yuusha had actually been kidnapped by a demon and brought here and it was the demon that slaughtered all the guards.
However all the hope that there was crumbled away when he saw the gruesome scene.
There was no demon inside the room.
No, there was.

And it was Yuusha.

"YUUSHA!" Ursus angrily shouted, anger could be directly heard from his voice.
Rei just silently looked at him and said.

"Ah someone troublesome has appeared again? What should we do? Eliminate? Eliminate." She said indiffirently.

"Pick up your weapon Yuusha." Ursus said, anger still stuck to his words which were condemning Yuusha.

"Ahhh, the third code of the Priscian Chivalry book...'thou shalt not strike down an opponent without a weapon'...was it?"

"It seems you are already well versed in it, despite only having been inside the royal library for a few hours."

"Well the book cover was already eye catching in itself, how could I not read it?" Rei casually answered back.

The Rule Book of Chivalry, it was the first book that Ursus had ever read when he was little, he regarded it as his life motto, and swore to stick to it at all times.
The fact that Ursus is still sticking to the code of chivalry 'Thou shalt not strike down an opponent without a weapon.' means that anger had not yet clouded his
judgement, however the fact he had just given Yuusha a chance to grab weapons was already a mistake in itself.

"But what about sixth code? 'thou shalt not hurt defenseless women'? Can you really call yourself a knight when you going to strike such a beautiful damsel down?"

"What defenseless woman hides a knife on her back and carries a spear on her right hand? And what beautiful damsel are you talking about? I see no such thing here...
Only an unsightly monster!" Ursus snapped back as he rushed forward, pulling out his rapier in an Iaido motion and it made sparks fly as it made contact with Rei's
spear and knife.

---

Rei responded with a low sweep kick that aimed to destroy his posture, however as if Ursus knew about it before hand, he swiftly jumped up and kicked the shaft of Rei's spear sendng her flying across the floor, Rei then let go of her knife, effectively performing an ukemi as she landed perfectly like a cat.

She looked at her hands as she held her weapon.

'So this is a mana technique!?' She felt her arms go numb when she clashed weapons, even now her arms were still shaking and having trouble gripping her tools.

Even though Rei had read all about mana techniques in the books, Experiencing up close was nothing short of horrifying. It was like humans built up stimulants and steroids inside of them to make their hits no less inferior to an artillery shell, The concept that literally anybody would make a city go up in flames just as long as they were born with enough mana terrified her.

'What terrifying physical strength.' Rei thought as she got upfrom the floor.

Although Rei's physical strength had improved as well because of her fusion with the Essence of Gluttony, it was still far off from Ursus' strength.
There were two significant reasons for that.

One was Rei couldn't use mana, no it was more like mana was rejecting her. She couldn't use the peculiar energy to further improve her martial prowess, or shoot laserbeams from her eyes like a specific DC hero.

And reason no. 2 was that, like all Sin Essences, needed time to make it's host unmatched, Pride required you to compile people that you could trample beneath your feet and Greed required you to accumulate your possessions to make yourself more powerful, and for Rei who had just barely eaten 3 humans ever since the successful merging of Gluttony, not only was she not even an ant when compared to Reina just before she died, Rei was also still suffering from the drawback of gluttony as well.

If it came down to pure technique, Rei was undoubtedly the better one, however the base stats and other abilties had to be considered as well.
Even a monkey who knew how to use a sword could never escape the sharp talons of an eagle.

Sword and Spear clashed, Rei would try to make an opening with her knife but only to be parried by Ursus' rapier.
As the battle went on, Rei's fatigue and hunger accumulated.
If this went any further she would be dead, and both Ursus and Rei knew that.
She needed something to turn the tide around, and luckily she just had the tool for the job.

Rei threw her knife and spear,and during the timespan Ursus deflected both with her rapier, Rei rushed to her guitarcase which she dropped, and pulled out a black metal object.

Projectile weapon?? CHECK
Armor Piercing Arrow?? CHECK
Quick Load Amunition?? CHECK

'Face the power of modern civilization you primate!'

To be exact it was a Luger P08 pistol used by the WW2 German Wermacht Luftwaffe Paratroopers, as for why such an old and outdated pistol was inside her guitarcase, it was more of a memento really from her past ventures...oh you were asking about why Rei carries guns to school? Well even back on Earth she was always being hunted down, and she really didn't feel safe at all coming outside of her mansion without a gun, it made her feel like she was going out naked even.

Rei now had a smile on her face, acting like she had already won, Rei with the second most happy geniunely real smile ever since she came to this world she said;

"Parry this you fucking casual." Rei said, her smile extending from ear to ear.
It was the most wicked smile she had ever put on for quite a while.

Perhaps sensing something bad was about to come, Ursus fixed his stance and pointed his sword towards Rei and Rei emptied all 7 bullets from the magazine on her pistol

*BANG*

*BANG*

*BANG*

*BANG*

*BANG*

*BANG*

*BANG*

"Wha--"

It was a voice that belonged to Ursus...not.

"How do you parry 7 bullets!?"

Rei, was in disbelief.

'It was supposed to be such a badass moment, when I showed him the hammer of modern civilization! Is something like this really even possible through training alone!?'

Ursus stared silently at Rei, but of course it was not like Ursus wasn't wounded.
Ursus had enough speed to parry 7 bullets, However he did not have enough skill to parry 7 bullets.
Ursus had deflected 6 out of 7 bullets, and sliced the last one, a fragment of the last bullet had embedded itself deep into Ursus' left shoulder, precisely hitting the gap of his armour.

The bullet had also effectively torn off the band of fibrous connective tissue connecting Ursus' shoulder bone, thus disabling Ursus' left arm.
A person would be naturally overjoyed at this, however Rei still thought of a plan to get herself out of the situation.
By the way the fight went, only Ursus' left arm was disabled...however Ursus was right-handed.
And the weapon that Ursus excels in is a rapier.

A weapon which was designed for only one hand.

"You've managed to wound me, i'll give you that."

Ursus had suddenly started giggling.
His laugh sounded like he was enjoying the current situation, no, it was like he was being sexually aroused.

"..." Rei picked up a knife from the ground.

"Fighting till the end, truly commendable, but one could only come so far without the help of magic...that weapon just now, was it a magic tool? It certainly looked
like a magic tool, however i felt no magic?"

"..." Rei hid the knife inside her sleeve, whilst picking another one in her left hand silently.

"Hahaha I see now, you've managed to last this long against me despite being magicless! You, who is incomplete and clearly hated by the gods! It is truly a commendable achievement!" Ursus once again fixed his posture, except his left arm was still dangling around motionlessly, at the next moment something made the hairs on Rei's skill stand up.

"This feeling...is it what they call an adrenaline rush?? I like this feeling...Yuusha, can I go serious for a second?"

Rei stared at Ursus in disgust, Rei and Ursus' attitudes had suddenly and mysteriously done a big 180°, both imitating other's previous attitude. Then all of a sudden
it felt like the air changed.

It was the feeling of magic converging inside Ursus.
Ursus' rapier coiled around like a spring, it had compressed like a spring until it had no more than a tenth of original length.
His rapier glowed a grey hue, as if sucking the surrounding particles into it.
For Rei every cell in her body only told her one thing, as well as the Essence of Gluttony seemed to be communicating with her.

'Dodge it, at all costs'

That's what it was telling Rei.
Rei picked up her guitarcase, as if shielding herself with it, however Ursus paid it no heed.

'It's all useless resistance' is what Ursus believed.

And he had enough reason to believe in his next actions, they were his trump card.

'You wield your strange otherworld weapons which know no orthodoxy or honour, however I wield my father's sword, and his father before him!' Ursus took one deep breath
before chanting.

"--AND IT HAS NEVER KNOWN DEFEAT! [Spring Thrust]"

The blade, which was compressed enough to make it look like a short cylinder, thrust at a lightning-fast speed, far surpassing the speed of the bullets which Rei had fired upon him earlier.
With speed almost impossible to see, it cut through the air like a hot knife through butter and pierced Rei's guitarcase.
However in that moment, Rei tilted her guitarcase, while the lightning fast blade was still inside of it.
Thus the trajectory of the thrust had been driven off of it's original course when it had come out from the other side of the guitarcase, grazing Rei's neck.

'A magic spell!'

At the next moment, smoke was coming out from the case with a rapid succession.

'He punctured one of my smoke grenades!' Rei thought, she could use this to her advantage and close the distance!

"HAHA YOU'VE MANAGED TO AVOID THAT! HOWEVER IT'S NOT OVER!" Ursus screamed.

His blade retracted, once again forming a compressed spring, it was then that the words '[Spring Thrust]' were repeated on clockwork and started stabbing and retracting
multiple times, ignoring the grey smokescreen in front of him.

"[Spring Thrust] [Spring Thrust] [Spring Thrust] [Spring Thrust] [Spring--"

Rei relied on nothing but sheer luck and instinct to guess which part of the guitarcase the blade was going to stab through, but unfortunately since her luck was literally almost non-existent, she had to rely on technique instead, by guessing the trajectory of the stab with only Ursus' hand movements alone.

Rei started to close the distance, still shielding herself with her guitarcase, as she could not change the trajectories fast enough while flailing her arms around, her wounds accumulated even though she was covered by a smokescreen, however that did not stop Ursus from spamming [Spring Thrust] just like a medieval keyboard warrior.
Ursus did not even bother using other magical attacks, as the sight of Rei attempting to close in and defending against his snipes filled him with ecstasy.

'This insane bastard!' Rei cursed inwardly.

Once Rei was within arms reach of Ursus she immediately hit his head with her guitarcase, and as Ursus fell down he lost grip of his rapier, Rei then took out her knife and tried to stab Ursus' forehead on the ground using her left hand, however Ursus moved in accordance and Rei's knife hit the stone floor,
Ursus' hand then grabbed Rei's trying to crush it with his strength, and that made Rei let go of her knife thus prompting Ursus to switch their positions.

Rei was now in lying on the ground with Ursus on top, Rei took out her second knife with her right hand and went on to stab Ursus' neck.

"[Animate Flesh]!" Ursus shouted.

And in the next instant, Ursus' left hand which was supposed to be immobilized made a cracking sound and then grabbed Rei's wrist prompting Rei to attempt to ease Ursus' grip with her left hand.
Ursus with his free right hand then grabbed the first knife that Rei dropped on the floor. Ursus then held the knife in his right hand in a reverse grip, and then brought it down to Rei's neck with supreme force, which Rei stopped using her hand.

"FUUUUUUUUU-" Rei screamed with a closed mouth, her face visibly contorted in pain.

"HAHAHAHAHAAH! YOU TRULY ARE THE BEST YUUSHA!"

The knife in Ursus' right hand stabbed through Rei's palm. Rei was forced to close her eyes due to the blood getting in her eyes however she did not put in any less strength in her hands. However Ursus' right hand slowly descended despite Rei's effort.

And just then something unexpected occured.

"GET OFF OF HEEEEEEEEEEEEEER!"

A figure wearing a Japanese highschool student uniform charged towards Ursus bumping into him and knocking him off Rei, after lookng at Rei to check if she was still alive, the figure then proceeded to pick up a sword on the ground and made a kendo stance.

No need to say, It was Ryuuji the motherfuckin' riajuu.

"Whos dares!?" Ursus recovered rather quickly and stood up on his feet, his face looking enraged, however when he saw the person in front of him his expression turned completey different in an instant.

"Why are you dong this!?" Ryuuji shouted, his face dyed in confusion.

"Hero! Please leave it's dangerous here!" Ursus' attitude had once again reverted back to his knightly self.
It was different if he was alone with his prey, however if there was somebody else in the room alongside him. the innocents took priority first.
'Thou shalt not put the innocents in danger.' The first code of Chivalry in the Priscian Chivalry Index clearly said.

"What do you mean it's dangerous!? All I see is a knight trying to kill a defenseless woman!" Ryuuji snapped back.

'Does everybody think that she's a defenseless girl!?' Ursus cursed. He picked up his rapier and held it in his hand.

"No that's wrong she's a monster! She killed all these people!" Ursus replied, closely inched towards Ryuuji.

"Haaa? What the hell do you mean? Rei is this true!?" Ryuuji asked Rei who was slowly getting up, her right hand wiped the her blood away from her eyes and then quickly
answered back.

"I didn't do such a thing! I was just taken down here with some escorts when he just suddenly arrived! He killed everybody who was with me, and then they told me to come to this chamber, and then he followed me and slaughtered everyone else who was left! Even though everyone was so nice to me...Huuuk~Huuuk~"

Rei lied as naturally as she breathed, even back on Earth her acting skills were polished to a degree that even actors from Hollywood would have to acknowledge her superiority.

"--he killed all those people just because I made Princess Listicia collapse! Even being a yandere has its limits!" Rei exclaimed.

The lies the she layered on top of another were so ridiculous, however it seemed so real that even Ursus was forced to shut his mouth.

"Hero just please trust me on this!" Ursus pleaded.

Rei was already on her own feet, and she picked up a knife and put it inside her pocket.

'I don't have enough time for this! I'll just evade anything Hero-sama dishes out and then incapacitate him, he'll understand sooner or later regardless!' Ursus thought.

"[Fleeting Rush]!" He rushed towards Ryuuji and as soon as Ursus was inside Ryuuji's reach something inexplainable happend.

Nobody who even had a slither of goodness left in them would ever thought about what happend next.

A bladelike object invaded his solar plexus, accurately hitting his vital points and it went all the way through him and protruded from his back.
It wasn't Ryuuji who had stabbed him, rather the long blade came out from his abdomen before striking Ursus.

"Wha--" Ryuuji was in disbelief, however that did not last long as the light in his eyes disappeared, fully indicating that he had already left this world. He had died without knowing what exactly what happend to him.
However Ursus, who was very much alive even after having stabbed in one of his vital points, a testament of his inhuman endurance as a knight.

"[Spring Thrust] was it? It's a rather nice technique, I think i'll take it." Rei said casually.
"You...bastard..."

'Was that luck? Was that actually luck?'

Rei didn't have anything that could even be considered as a sword, and instead in her left hand was a rapier that could stretch longer than a spear at lightning-speed that was made of an unknown material originated from the still-bleeding hole on Rei's palm...It was her first manifestation of Aether.
And in her right hand...was a human heart.
Ryuuji's chest was caved in, his ribs looked sucked in and the colour from of his face looked very pale even though he just died seconds ago.
As if someone had ripped out his heart from his back with their bare hands.

'I think I figured it out...nourishment absorption absorbs about 90% from the heart...well it's a rough estimate but I'll do more tests later.' Rei thought as she ate Ryuuji's heart in one bite.

"You...MONSTER! You killed him!" Ursus shouted as his own consciousness was already fading away.

"Hmmmmm? But you were the one who killed him though?" Rei answered casually.

"What...shit are you spouting out?" Ursus retorted, barely holding on to whatever what was left of his dear life.

"Because of you, Because you didn't finish me fast enough, and because you let your emotions play with you, your 'Hero' is dead, and there are only three left. Did your mother not ever tell you to not play with you food?" She asked him in a mocking tone.

"Don't you...talk...about--"

'--mother like that!' or so he tried to say, but his voice wouldn't come out. 

"When food is being fed right in front of you, You have to eat it all...as fast as possible, before the one who gave fed it to you changes their mind." She said.

Rei then procceeded to retract her Aether, and the hole on her hand was quickly plugged up, as if a hole had never existed there before.
And before both bodies hit the ground, Rei tore off Ursus' rapier from his belt, and took whatever money he had on him and ripped his heart out and then consumed it.

"Or so I say, but I like to play with my food too, it...amplifies the flavour you know?" Rei asked Ursus.