“… Fine, I accept your challenge.”
 
Sona lets out a positively keening noise at this, one that starts in the back of her throat and stays there, making her sound like a tea kettle if Issei’s being honest. The Student Council President looks beside herself with his decision to humor her older sister. But to be fair, Serafall Leviathan is literally one of the Four Great Satans. Did she really think that her big sister was going to leave them alone if he said no?
 
Meanwhile, Serafall beams, the brightly dressed Satan actually leaping up in the air, pumping her fists over her head in what HAS to be an anime move. Sheesh, she really is committed to the whole Magical Girl Act, isn’t she?
 
“Excellent! Then I, Magical Girl Satan Pink, will defeat you, fiend!”
 
Cocking his head to the side, Issei just shrugs.
 
“Should we move this somewhere else? Pretty sure you don’t want to blow up your sister’s school. Actually, should we go all the way to the Underworld for this? There’s probably some empty plot of land you would know about that we could fuck up while fighting and no one would care, right?”
 
At Issei’s suggestion, Serafall blinks and then giggles and waves a hand airily.
 
“Oh, I’m not going to be dueling you, silly!”
 
Wait, what?”
 
Issei raises an eyebrow, even as Serafall does a little twirl.
 
“This is a challenge for So-tan’s heart! Which means I need to prove that I can beat you in an arena where you’ve already proven yourself! After all, how can I lay claim to my precious sister if I cannot take care of her… n-needs?!”
 
At that last bit, Serafall goes full… kya-mode, for lack of a better word. Planting her gloved hands on her cheeks, the Pink-clad Leviathan blushes profusely, and Issei is pretty sure he sees literal hearts in her eyes for a moment. Is that… is that a magical effect of some sort? How is she DOING that?
 
The overly dramatic act that she’s putting on makes it hard for everyone else in the room to process her words in any sort of reasonable time frame. However, Sona manages it first, being more inured to her sister’s eccentricities than anyone. Issei is just catching up as Sona’s eyes go wide as saucers and she begins sputtering, shaking her head in disbelief.
 
“N-No! No way!”
 
Issei, meanwhile, is starting to grin wickedly. Is the Leviathan really suggesting what he thinks she’s suggesting? If so… she’s fucking on. And because it was embarrassing Sona SO much, Issei can’t help but lean into it a bit. Putting on a mock serious face, he plants a fist under his chin, holding onto his elbow with his other hand as he slowly nods.
 
“Hm. So our battlefield… is to be Sona’s body?”
 
Sona positively shrieks at the sight of him playing into her sister’s games.
 
“ISSEI!!!”
 
However, more interesting in Serafall of all people’s reaction. The older sister to Sona Sitri goes bright red and for the first time seems legitimately embarrassed as her eyes dart over to her stricken sister, only for the smallest droplet of blood to escape one nostril.
 
“N-No, I haven’t… I have not yet e-earned the right to lay these hands of mine upon my darling So-tan in such a way! I must d-defeat you first, fiend!”
 
The room falls silent at that declaration, with Sona looking utterly flummoxed that her sister was backing down from the chance to molest her, and Issei furrowing his brow.
 
“Then… what? A sex battle just between the two of us? To see who can last the longest?”
 
Once again, Serafall shakes her head.
 
“That would not be fair… to you! It is notoriously harder for a man to make a woman cum! I would have you on your back begging for mercy in moments! No… no, we shall indeed make a battlefield of someone else’s body… and since this matter is a matter of So-tan’s heart, who better… than her Queen?”
 
Until this point, Tsubaki had been able to almost completely fade into the background. Dressed in a slutty version of her Shrine Maiden attire, Sona’s Queen had been almost completely silent since the arrival of her sister. Beyond that one comment, Tsubaki had kept to herself… but now, as Serafall’s eyes pin her in place and both Issei and Sona swivel their gazes over to the young devil as well, she freezes, her own eyes widening as she gulps audibly.
 
“… Sure, I’m game.”
 
“… Eep!”
 
Issei grins at Tsubaki’s squeak, before glancing over to Sona.
 
“What do you say, ‘So-tan’? Shall your sister and I decide your fate and just who you belong with upon the body of your Queen?”
 
Now that it wasn’t her own body being discussed as a sexual battlefield, Sona actually manages to regain some small measure of her composure. Face still bright red, cheeks still aflame, she nevertheless reaches up and pushes her glasses up the bridge of her nose as she swallows nervously.
 
“… I-I suppose if you m-must…”
 
“S-Sona!”
 
Now its Tsubaki’s turn to look betrayed, but Sona just turns her red face aside, averting her gaze and refusing to look her Queen in the eyes. Stuck between a Dragon Emperor and a Great Satan, Tsubaki can do nothing, shoulders slumping as she resigns herself to her fate. Issei, meanwhile, looks over at Serafall and raises an eyebrow.
 
“Terms? Rules? How do you want to do this?”
 
“We will take turns! Each of us will get thirty minutes to make Tsubaki cum! We’ll flip a coin to see who has to go first, that way its fair!”
 
Raising an eyebrow at the time, Issei just smiles and shakes his head.
 
“I’ll go first, if you like.”
 
For a moment, Serafall looks confused… then, her eyes widen as she looks at all three of them, seemingly just remembering what they were doing before she arrived.
 
“Wait, no! I want to go first!”
 
… Seriously, how much of the Leviathan’s act was actually an act, and how much was real? Because she was REALLY good, if all of this was little more than an act. Still, Issei hums… and then shrugs.
 
“Sure, fine by me.”
 
Serafall grins as if she’s won some great triumphant… and begins to saunter her way over to Tsubaki. Issei watches, amused, as Sona pulls a timer out of nowhere. Leave it to the Student Council President to ALWAYS be prepared.
 
“T-Thirty minutes! No longer! Your time, sister… s-starts now!”
 
Without skipping a beat, Serafall plops down next to Tsubaki on the couch where the Shrine Maiden is sitting and cozies up to her.
 
“Hey there, Tsubaki~”
 
Blushing up a storm, the bespectacled, buxom young devil shivers as she looks at Serafall, equal parts mortified and embarrassed.
 
“H-Hello…?”
 
Seemingly realizing that seducing Tsubaki with words was out of the question and that her status as both Sona’s big sister and the Leviathan were working against her here, Serafall almost immediately changes tact, and for the first time, Issei gets to see a hint of the real devil underneath. All of the sudden, she’s not just cozied up to Tsubaki, she’s pressing against Tsubaki, molesting her through the opening in her top and licking at her earlobe, her neck, her everything.
 
“Right, sorry. This is what you want, isn’t it? You like it… rough.”
 
Tsubaki whimpers and squirms, but all the same, the effect on her is… pronounced. Serafall is right after all, Tsubaki DOES like it rough. She likes being taken, as evidenced by his first time with her, when she’d all but thrown herself at him while pretending to be trying to exorcise him as a demon or something. Heh… good times.
 
Still, as primed and ready as Tsubaki is to go thanks to what she, he, and Sona had all been doing before Serafall’s arrival, it’s clear that Tsubaki’s healthy respect and fear of Serafall are still holding her back. But ‘Magical Girl Satan Pink’ isn’t a quitter, and the Leviathan doesn’t seem inclined to let a little thing like fear hold her back.
 
Pushing Tsubaki onto her back all of the sudden and lifting her legs up into the air, Serafall leans over her, grinning wickedly as a hand goes up under Tsubaki’s skirt and very audibly begins fingering away at her slick wet slit. As Tsubaki gasps and moans and whimpers, Serafall puts things into the next gear, even going so far as to lower her mouth to the shaking, jiggling tit that’s popped out of Tsubaki’s loose Shrine Maiden top.
 
Honestly, it’s a very attractive sight, and despite Tsubaki’s clear recalcitrance, Serafall is getting through to her anyways. As the minutes pass by, Tsubaki is slowly but surely turned into a puddle of pleasured goo by the Leviathan… and at minute twenty-five on Sona’s timer, Tsubaki finally crests, her loud, lewd cry filling the room as her back arches and she spasms, squirting quite visibly all over Serafall’s hand.
 
The fact that Sona’s Queen just came is obvious to all, but Serafall makes a point of showing Issei her messy hand before licking it off with a cheeky grin.
 
“That’s my win, I suppose~”
 
Issei just snorts in amusement and shakes his head.
 
“Not much of a competition if I don’t even get a turn, is it?”
 
That causes Serafall to blink, and Sona to speak up from his side.
 
“He’s right, s-sister! This has now become a matter of… of time. You made Tsubaki c-cum in twenty five minutes… so Issei now has the opportunity to beat your time.”
 
As if she hadn’t thought of it that way, Serafall suddenly looks a little worried. Glancing down at Tsubaki, she gauges Sona’s Queen’s current state for a moment. Laid out on the couch, eyes heavily lidded, Tsubaki is breathing in and out rather shallowly, as if she’s barely conscious.
 
“… Very well, b-but then if he beats my time, I get a chance to beat his, right? And we keep going until one of us can’t beat the other’s time?”
 
That was only fair. Glancing over at Sona, Issei watches as the Sitri Heiress is forced to reluctantly concede the point with a grimace and a nod.
 
“… Yes, that is how it should be.”
 
Beaming now, Serafall hops up from the couch and practically skips over.
 
“Very well then! Go ahead, fiend! See if you can beat my time… and know that even if you do, I will still overcome anything you can manage! This I swear, as Satan Pink!”
 
Issei doesn’t respond, not verbally. He’s already decided he’s going to let his actions do the talking. Moving over to Tsubaki, he carefully picks her up off the couch and sits her down in his lap. She jolts back to life the moment she feels his cock come up between her thighs, poking up under her skirt and rubbing against her creamy, pale flesh. A cute little mewl leaves Tsubaki’s lips, and despite the audience, she can’t help but rub her thighs against his cock, giving him an impromptu thigh job right there on the spot.
 
Issei, meanwhile, completely pulls Tsubaki’s top open, and grasps her tits directly. Like Serafall said, the bespectacled girl liked it rough… but just giving it to her hard and fast, while it would deliver results, wasn’t the end all, be all. If there was anyone who knew Tsubaki’s body as well as she did, if not better than she did… it was Issei Hyoudou, who had conquered her, tamed her, and explored every inch of her.
 
Lifting up her skirt, he brings his fingers to her clit… and pinches it hard while pinching her nipple at the same time. In an instant, Tsubaki cries out… and squirts all over his throbbing shaft, right in front of Serafall and Sona. Immediately, Sona stops the clock.
 
“T-Time! Thirty seconds is the new time to beat…”
 
Sounding downright relieved that Issei has set what has to be an impossible record, Sona’s shoulders slump… heh, as if its over. Serafall, meanwhile, looks gobsmacked. Before either sister can do or say anything else, Issei just shakes his head and grins.
 
“I’m not done yet. I still have twenty-nine minutes. Just because Satan Pink didn’t use all of her time… doesn’t mean I can’t use all of mine.”
 
He’s changing the rules on the fly for sure, but then, that’s what Issei does. Sona goes bright red and amusingly enough, so does Serafall. Tsubaki, meanwhile, can’t escape him… not that she wants to. As he plays her body like a fiddle, she cums for him under his touch again and again. Each time is purposeful, each time is precisely when Issei means for her to cum. Each time, he makes eye contact with a progressively paler Serafall as he makes Tsubaki squirt for him.
 
At the fifteen minute mark, Issei finally lifts a mewling, moaning Tsubaki up and impales her on his cock. She’d been begging him to fuck her under her breath for some minutes before that, but only now, with half of the time left on the clock, does he slam Sona’s Queen down upon his member and begins fucking her. Needless to say, she squeals like a stuck pig and cums yet again, just from the penetration. Then, she keeps on cumming, a mess of a continuously moaning girl bouncing up and down on his cock, half-rag dolling already as she shivers and shudders and spasms, her legs kicking about, her arms flailing.
 
Nuzzling her neck, Issei looks Serafall right in the eye and keeps looking at her, staring the Great Satan down until the timer finally finishes. By the end of his allotted thirty minutes, he’s made Tsubaki cum an uncountable amount of times… though, if pressed, he’s pretty sure Sona knows the exact number anyways.
 
Issei just pulls the insensate girl off of his cock and sets her down on the couch before standing and lifting a single brow, undeniably amused.
 
“Your turn, if you want to try and beat that.”
 
His tone is teasing, because they both know Serafall couldn’t beat his ‘score’ in a million years. Especially not with Tsubaki outright lost to the world now. Not just satiated, but entering a full blown pleasure coma, its obvious that Sona’s Queen is going to be rather unresponsive going forward. Even if Serafall tried, she wasn’t likely to get anywhere.
 
“… D-Double or nothing!”
 
Issei blinks.
 
“Excuse me?”
 
“You’ve won this first challenge, that I cannot deny. O-On my honor as a Magical Girl, I must concede. B-But… if you would be willing to do double or nothing, then I can sweeten the pot. This time… it will be just you and me! A proper sex battle. If I win, I get my So-tan. A-And if you win, you get me… and my Queen!”
 
“W-WHAT?! S-Sister, you can’t just offer up Rei like that!”
 
Serafall… pays her little sister no mind, instead staring him down intently, waiting for him to make his decision. Because the truth is, Sona is wrong. And whether she’s being naïve about things or just morally objects, the fact of the matter is, Serafall CAN offer up whoever this Rei woman is as collateral in a double or nothing bet.
 
The only question is, does Issei truly care to take her up on her offer? He could just have Serafall and Sona here and now and be done with it. The Leviathan has already lost. Is it really worth continuing to jump through hoops for Serafall’s Queen, whom he’s never even met?