Yeah, Mirai, I really didn't get that line: based on everything we know so far, the temporary duration of V's vacation in hell has already been set in stone (with the splices having been removed from the equation entirely, there's no greater benefit from a time-in-hell perspective that the demons can look forward to once V dies. However long s/he's been timed for damnation, it's a fleeting period unless V's alignment has changed entirely.)

So it seems like there's another reason entirely beyond what little we know for the demons to root for V to continue to live. Perhaps they sense V is already treading into dangerous, evil waters...maybe they suspect s/he will fall even further of hir own volition...

I think that they very much intended on her falling from grace right-and-proper by just giving V a gentle nudge and the tools to do it with. So far she's acted 100% according to the Evil alignment, (Necro'ing Dragonmommy to show her the Familicide spell) and even with her power taken away she's already done everything The Bad Way.

But that confuses me further - I'm guessing that they were tempting her to fall from grace, which she did...so she's now well and truly Evil...so why keep her alive? If she's Evil they did their job, or maybe its to have her face the fact and be forced to accept that, yeah, you're totally on the Evil side of the street now, get used to it.

Which I can't see benefiting them other than cause it's funny, unless there's something we don't know.

What would you think when you're looking for an invisible intruder and a closed door suddenly opens on its own?

I'm thinking that V's soul is more useful while still attached to the body. If V dies the fiend's can just rent out/torment his soul. But if the soul still resides in the body its possible they'll also gain control of the body (which is far more useful considering they already have the souls of far more powerful beings to bargin a soul splice with), or even better cause the spirit to expel itself from the living body and thereby gain a permanent vessel (body) as V's spirit wouldn't be able to return if the body is already occupied by a soul of the fiends' choosing.

That's just my guess.

The benefit for V surviving is him going on to do more evil stuff. She has to do some more worl-shatteringly evil stuff before their organization is taken seriously. Killing a bunch of evil dragons out of spite is a good start, but how about killing a bunch of gold dragons or something? Something beyond the normal deal with the devil stuff.

In the alignment sense, it's not about reaching an end destination. It's not about making her Evil in the sense that her actual alignment changes (and I'd still say it's not a full blown change to "Alignment: ____ Evil" just yet, regardless of the fact that she was in control of herself when she had the power, but that's a debate I really don't feel like getting into again). It's about making her walk the path. There's no end, except death, which is the end for everyone regardless of alignment.

Now I'm assuming they actually have some goal in all this aside from just that - maybe something involving some kind of fate V is destined for - but as far as corrupting her goes; It's easy to corrupt someone. Convince your friend to fake sick or cut class one day. Wow corruption. Getting them to be the kind of person who cuts class constantly, eventually drops out of school, and ends up becoming a career criminal or something - is different. You're not doing it so you can hit them with a rubber stamp that says "cut class" or "evil" in this case. They'll still be the same person afterward. The important thing is the actual path they take through life. That isn't made up of a single choice, or any number of choices, really. It's all the choices. It never stops.

Miko thought it did. She thought that she was Just and that was it. Look how that turned out.

It's like how being married for ten years doesn't mean you had a successful marriage. If you divorce tomorrow, it failed. It only ends successfully when you die (preferably not murdered by your spouse). Otherwise, it's always in flux. It carves out a path, but the path doesn't end (death aside), it just goes on. Of course, no one's going to say it was anything special unless you made it through fifty years of marriage or some similar number before the whole death thing. But when you do die, they're not going to say "hey they died. They had a successful marriage." They're going to talk about what you did in marriage and all the lives you touched. And even if the marriage fails, it's all still part of the greater path you carve through life. You could even divorce and remarry. The path never stops being carved.

If corruption is all the fiends are going for; then just being able to put the "evil" stamp on V's forehead isn't enough. They want her evil to carve a path, and touch lives in its own way. Obviously she's already done some big things, but that's still not the same thing.

Edit: To sum everything up: It's not about making her Evil with a capital E; it's about making her be evil.

Edit 2: And I know there is actually SOME point to the end in D&D, but they've already made it pretty clear that getting V's soul really doesn't matter to them.

The three fiends have two goals

1. Something to do with the gates. They know that the gates exist, that three have been destroyed, and that Xykon thinks he can control the snarl's power through them. Obviously they want to stick their hands in the situation.

2. Get V to do a ton of evil stuff, so that his proper afterlife is one of the three lower planes (and also so that a ton of evil stuff gets done). The soul splice paid off so far, but right now V is very close to dying in defence of the world's safety with only one really terrible act to his name. He's all but certain to come out morally neutral if he dies at this point in time.

I figure the goal with making the deal with V is to make him addicted to the power so he'll end up giving his soul wholesale for one more fix. And if he dies the chances of making any more deals for his soul go down quite a bit as he'll find Hell isn't very nice.

They could have had that right away. V was all but falling over himself to make that deal when they came up with their terms.

It's long past the point where anyone can sensibly delieve that the IFCC is playing the typical Faustian racket. These guys are smoother operators.

I mean, not only did they give V awesome power without any "strings" in the form of compulsions to do evil, they lied about that, suggesting that he may experience "some alignment based feedback" when in fact such was not the case. They've already admitted that they structured the deal in order to place V in a situation in which they judged him likely commit terrible evil entirely of his own free will.

Well, yeah. But they've still already made her do all these things. She's already right and proper damned, as I said, so what exactly could matter about her staying alive longer?
...okay that makes a bit more sense, yeah, but I'd have a hard time (as a DM or player) believing someone could do all the stuff V's done with the soul splice and still just catching 'neutral.' She's already been neutral, as indicated by her disproval of helping out the Azurite refugees ("While I find their situation distressing, we have more pressing matters to attend to," or something), which means the mad-with-power has bumped her over to the other side.

Belkar pretty much said exactly that, and I know he doesn't have an 'in' on the way the comic works, but still.
This seems like the most likely of scenarios, since Sabine already told them about it specifically.

EDIT: Why am I saying "She" in reference to V? I was firmly on the side of 'male' for so long.