Holy necromancy Batman!
But yeah, I'm on the GM's side on this one as well. There are some 1-shot-I-WIN combos that both players and GMs alike should just have a gentleman's agreement just won't work.
Using said combo during the epic battle against an opponent that a majority of the AoW have been building up to is among those things.
It's about the same level as having some bard max out his Diplomacy to +107 by the end of the campagin.
Que the FINAL BATTLE AGAINST KYUSS!
Epic ++diplomacy player: "I tell Kyuss that he's a ducebag, and that I want him to serve me for all eternity. And grant me 9719027309 gp worth of stuff. Oh, and I tell him his mother was a hamster." -rollrollroll- "My modified Diplomacy check is 110... I suppose you are going to hit me twice with the -2 modififer, but according to the rules for Epic use of Diplomacy, Kyuss is now a fanatical follower of me. We win guys!"