Chain Lightning!

Mephistopheles grimaces. "That's not nice," he says as he skewers Garrus again.

The Valsharess shrieks as the lighting courses through her, but shakes it off and cracks her whip in Deekin's direction.

Deekin wails and falls from his couatl steed, which dissolves into light.

Will the Valsharess disintegrate if Belmarniss asks very, very nicely.

She makes her save, but even the reduced effect drops her to one knee.

"Mephistopheles, you useless creature, kill her!"

And the archdevil grins.

"I think not... dread Valsharess."

He drops Garrus from his trident, teleports behind the drow, and impales her.

Her eyes widen, then roll back in her head as she dies.

Mephistopheles turns to Belmarniss and shakes his head genially. "Some people, really... Hello, Belmarniss."

"...uh. ... hi?"

He chuckles. His barbed tail lashes like a satisfied cat's. "You've done magnificently, I have to say. I'm really quite impressed! You're not as much of an out-of-context problem as I might have thought, but that's what I get, I suppose, for reaching into such a close reality."

"...what do you want?"

He shakes his head. "What don't I want! The Valsharess was so unimaginative, you know, thinking she could be content to conquer the world. But I suppose I'll tell you what I want, ah, proximally."

His tail hovers in front of him. It's a standard, barbed devil tail - but at the end, it's neatly truncated. The barb's tip, the arrow's head, is missing. "You, my dear, have something of mine."

In Belmarniss' pocket, the Relic of the Reaper shivers.

"If you wanted it you could have picked it up back when I was still trying to pawn it."

Mephistopheles chuckles. "Oh, I don't want that."

The Relic hovers out of her pocket and hovers in the air between the two of them.

"I want everything else."

The Relic turns and plunges into Belmarniss' heart.

This kills the Belmarniss.

"Greetings, Belmarniss."

The Reaper's voice is melancholy.

"Hey. Does the blursed object work if it's the thing that kills me?"

"I am afraid that the Relic is no longer yours to command," the Reaper confirms. "And... I would not be capable of defying Mephistopheles, in any event. He has condemned you to his realm: the Eighth Hell, Cania."

"I took up religion to avoid this exact sort of thing!"

"I cannot possibly apologize enough. But - he has my True Name. And circumstances have aligned such that the gods cannot step in."

"What circumstances?"

"He has taken advantage of ancient compacts, which none thought would come to pass. Most of the gods cannot even see that he has done so. Those who have, such as Eilistraee, have their hands tied. When he called you to Toril, he introduced you as an outside agent, one from beyond prophecy's reach, and then - he took your place. In the eyes of divine law, he is free to roam as any mortal would - and you, bound exactly where you belong."

"...I don't think I understand, prophecy doesn't work anymore on my planet."

"It is difficult to explain. It is not because of prophecy that he can do this, though he used prophecy liberally to arrange matters in his favor. The... understandable summary which is not entirely incorrect... is that the gods cannot intervene because, legally, Mephistopheles is now a mortal, a free agent rather than an agent of Hell. And he was able to consign you to Cania because he possesses my True Name."