Sam sighed in the Nexus. He felt a bit useless, and his use in this world was just to be a breeding stud for warriors. 

"So much for the cowardly hero. All I am good for is summoning more warriors. Not a bad deal though. I don't face much danger, don't get injured much, fuck alot of pretty girls that look like famous actresses. I should be happy with this new life. 

But it's so different from all the isekai stories where the hero gets great powers and abilities and become real heroes. Most of them have great backgrounds in their previous lives, but all I am is this loser who gets killed by robbers and his crush" he thought to himself as he stripped naked and lay on the ground.

"Oh well. Nexus, I would need another demon slaying warrior" he commanded, getting ready for the next summoning. 

Instantly his body stiffened up as he felt his body clench. Every time this happened it was very uncomfortable until the time his body separated from the summoned familiar, after which he is balls deep and feeling nothing but pleasure. But this part, he wished he could do without. It feels like every muscle in his body was nearly cramping up, right on the verge but he could not relieve the pain. 

He wished he could hurry whoever it was up, but he had to patiently wait as lips formed around his erect penis. 

He watched patiently as a brunette head formed around his cock, swallowing it into her throat and she pushed herself out of his body with her arms. 

She managed to turn around when he recognized her as Faith Lehane, the other slayer besides Buffy, and acted by Eliza Dushku. 

Sam waited impatiently in pain as Faith discovered how to exit his body through memories transmitted through his mind link. 

Suddenly, they separated and Faith gasped from suddenly being filled. The mind link already brought her up to speed and she looked around seeing the battle being fought outside.

She simply smiled and started grinding on his cock, enjoying every moment. Faith was very sexual. Being the "dark" slayer, she seemed more in touch with her sexuality and knew all the right moves, making Sam cum pretty fast. 

However, even after he came inside her, she continued fucking his still erect cock. 

"Uh.. Faith? What's going on?" Sam asked. 

"There are so many of us, each won't have much time with you. I might as well take advantage of my time alone with you. How often will this happen anyway?" she said. 

"But Buffy and the others..." he said. 

"Buffy is Buffy. She will prevail somehow, or at least survive. Besides, you can always revive us, so this is a non issue" she said, kissing him again and fucking him hard. Sam eventually relented as she was very very good at what she was doing. 

Finally, many minutes later, she finally got off him, leaving him exhausted and lying in a pool of his own cum and her juices. 

"Ok lets go" she said standing up. 

"Uh... let me get dressed" Sam said as he got up. 

"Nevermind, I'll go first" she said, jumping out of the Nexus, completely naked. 

By now, the demon was already nearly entering the town, and his lava breath had already burned the nearby walls down as well as several houses closest to the wall. 

As she exited the Nexus, Hermione cast a spell creating clothes similar to Buffy's clothes, namely black lycra pants and spaghetti strap lycra top. Apparently they had been communicating in the mind link about the design of her clothes in preparation already. 

She ran towards where Buffy was and avoided an attack by somersaulting. 

"Hey Buffy! Give me a weapon!" she yelled. 

"What happened to your knife?" Buffy yelled back. 

"My knife is pretty, but of no use against this demon. Give me the scythe" Faith yelled again. 

"You wish!" Buffy replied.

"Then how about Olaf's Hammer?" Faith asked again. 

Buffy nodded and out of nowhere, she was suddenly holding a huge hammer, formerly owned by Olaf the Troll God. 

She threw it to Faith who grabbed it in midair and slammed it onto the demon. 

*BAM*

The demon stumbled back, shocked at how powerful the strike was. 

Buffy followed up, slashing a large gash onto the demon's arm. It roared, preparing to breathe lava on her when..

*BAM*

Faith attacked again, smashing the demon's face.

Avada Kedavra!

Hermione cursed, pushing the demon even further backwards, as molten metal bits from bullets peppered the demon's face unceasingly. 

Merlin conjured a large fist out of energy, punching the demon in the stomach area as Buffy slashed at its throat. 

Both Buffy and Faith attacked with their magical weapons, and together with Hermione and Merlin's spells, and the long range bullets from the others, they managed to stop the demon from moving towards the town. 

In fact, they were actually pushing it backwards, getting it further and further away from innocent civilians in the town. 

"Ok here" Faith yelled, as they had come up with a plan in their mind link. 

Buffy sliced the back of both knees of the demon, causing it's knees to buckle, Hermione cast another killing curse, causing it to pause for a split second. That was when Faith smashed the demon right in the face, causing it to fall down backwards onto the floor with it's legs bent backwards under it's body. 

While it was lying down uncomfortably, Faith kept smashing it in the face over and over again every time it tried to move. Furthermore, Hermione cast a binding spell on it's arms. It was practically helpless and at their mercy. 

However, while they managed to restrain the demon, there was nothing they could do to permanently injure or kill the demon. All damage done to the demon would be healed within minutes. Its regenerative abilities made it impossible to kill. 

"Such demons cannot be killed by conventional means. It needs to be banished!" Merlin said to Sam. 

Hermione nodded. "While your new demon slayers Buffy and Faith seem powerful enough to fight it to a standstill, we still need demon magic to banish it. Otherwise, we will run out of strength and stamina while the demon will charge on and eventually kill everyone without getting tired. Unfortunately, I am not familiar with demon banishing magic" Hermione said

"As am I" Merlin added.  

"Shit, another summoning? How many times have I fucked today already? I am currently... shit, I'm only level 13?" Sam thought to himself. 

"Can you summon someone with such abilities?" Merlin asked.

"I.. I'll try" Sam said as he vanished into the Nexus again.