My advice to my fellow DM's is thus:
A player's ears are in their back and they hear best when they are beaten.
If the player wins. Congratulate them. Shower them with praise. Then murder them as hard as you can. This sort of behavior cannot be tolerated. As soon as one player wins, the rest might start getting ideas, and then where will we be? I suggest the souls of 875 dead bugbears who died without knowing they were killed because of the sudden trauma of death by nuke might just rise up as a hoard of ghosts to sweep out over the land in a green fog, not unlike that part in LotR: Return of the king.
There's a reason people don't go applying massive explosions in D&D. Hell, just the effect of that many sudden deaths in a small space by spell should create a Living Spell from HELL. A living Nuke Spell wandering about, powered by the angry vengeful souls of murdered bugbears.
Seriously. Get your twisted DM cap on, Write yourself up a epic level Living spell of Death, and let it go washing across the land in a random direction, devowering all that lives. Mention something about "Dark Sun" and "The rise of the brown age". Then sit back and grin like you planned it all along.
