Maybe it's because I just played through the game first time, but I see no issues logically with Vega and any of the other girls falling for the MC and choosing lewd/sex acts against him. Remember, since the beginning of the game, he has been in possession of the Shard of the Orc Kings Dick, which grants 'strength and endurance' during sex acts. While the Level 2 upgrade to get the x2 to x5 stat boost is the main focus soon after, I think the explanation for the girls going immediately to sex related acts has to do with the base ability of the shard.
I mean, some level of suspension of disbelief is necessary, and I think this part of the AVN just doesn't mesh with my style of humor or preference regarding intimacy. The "cheap" first times (drugged LI or needing to charge the artifact) are about the worst motivators to have sex, in my opinion. That the girls fall for the MC easily enforces a power fantasy, but the context around their intimacy feels wrong to me.
Vega cursing the MC as a way of torture and then proceeding to have sex with him doesn't do it for me either. Like I said earlier, she's a fierce noble, so the power fantasy isn't the MC lasting for an hour of intercourse, but her lowering her station and begging for his cock.
What we get is a woman who tricks herself into having sex with the MC (same as Sora) and later rewards him with a mansion to apologize. It just doesn't work for me.
It's very obvious how the 'endurance' plays out, but 'strength' is a lot more broad a term and considering it doesn't grant a buff to his 'strength' stats. So how are we to interpret the effect, just that he's better at sex? MC has endurance and a 12 inch python, that's doing all the heavy lifting. It makes more sense then that by 'strength', he basically has a sex aura about himself that conveys 'strength' in sex to those he's interested in. This also aligns to the actions of the various girls he comes across, that as soon as he's interested in them (be it verbally or his internal monologue that we read) they start to get turned on and fall for him. You can also see this narrative visually by blushing or increased blushing as things go along.
I don't think the shard is giving him that kind of aura, and I sincerely hope it doesn't. I'd rather play an MC who is irresistible than one who has an item that influences women. Ask yourself what is more interesting, having an item that makes women lust after you or having them lust after you because you're a great guy with a fun personality who's also in good shape?
But, I'm not even criticizing that part. What I'm saying is that Reyla's 2nd chance while camping at the lake is much more my style of intimacy than her getting fucked for the first time because she stepped on a mushroom. At the lake, she wants it and expresses an active interest. When she's drugged, it's more about not minding that it's him and that it's a necessity to survive. A big difference.
The same goes for Fraya. I call it a
cheap first time because it is, in a sense, thrown away. The narrative makes sure that we know she's
pure but then does nothing with it. She needs no convincing; she doesn't even remark, "This isn't how I imagined having my first". If Rayla were experienced or even promiscuous, then her being in that situation and quickly deciding to have sex would make more sense.
Here as well, the power fantasy doesn't work because external factors push them toward sex; it's not the LI who desperately wants to be with him.
Good example is the princess. Dialogue wise we realize he is trying to avoid wooing her the entire time, but also quite attracted by her such that he cannot help his interest from their first meetup. Even with his cold responses after saving her in the dungeon and leaving, she's blushing up a storm so her switch is obviously flipped. Then we see her go to the trouble of bringing Vega back into the narrative to find the MC (which he continues breaking Vega further later due to the opportune proximity), but remains distant to the princess. Then later the MC and princess finally go at it after a full week spent in close proximity. The 'strength' of the shard / aura breaking her down, yet even still a small push from the succubus to push MC is needed.
Let's disregard the shard and just say that the princess becomes more infatuated with the MC for whatever reason.
The MC needed a push because he put the princess on a pedestal, was conflicted about politics, and did the typical man-thing of not reading signals.
This scene works better for me when I tell her to leave the room and she admits to wanting it desperately. But again, using Vel's powers here is cheap. It's lazy writing, in a way. Yet again, we need an external factor to get to intimacy. If it wasn't for Reyla's 2nd chance, I would think the dev just doesn't know how to write seduction and erotic tension.
And Vega... I just wished sex scenes with her weren't mandatory after the first one. I'm not into the huge ass/huge tits thing, so the MC lusting after her
because boobs is just alienating. I don't think she has really redeemed herself either. And pranking her after she touches the shard the first time by sending her home to be horny for a week would've been funny and a lighthearted way to get even. The game is already playing fast and loose with the charges the artifact contains, so letting players avoid scenes wouldn't be a narrative issue, I think.