So i have a PC who has munchkined the hell out of his character, i try not to second guess their build but his character has destroyed every challenge i have thrown. He is a troll w pimped out military armor and all the fixings, w mystic armor his total armor comes to over 40/40. His attacks and str are ridiculous and he has arcane arrestor so mages have a hell of a time affecting him (they usaly don't get a chance w his adrenaline surge). Tranq darts dont work due to military armor, and with the party nothing last much longer than one round. Any advise to challenge this PC?
Before I start, let me say that this is entirely your fault for allowing the character into play to begin with. One of the DM's primary responsibilities is to check over charsheets before play to make sure that broken crap like this doesn't see the light of day. For that, you should be beaten about the head with a phone book. Now, as far as suggestions go:
1) Does he sleep/eat/bathe in armor? No? There's an opening.
2) Someone running around in heavy milspec armor, whether they're a troll or not, is going to be VERY noticable. Not only that, but his teammates will be very noticable, too. They should all be getting some heavy notoriety just from being around him, bounties posted on their heads, their contacts should be drying up because they're just too hot, etc.
3) Question the build. Question it long and hard. Honestly, a build that obscene should never have been allowed in play to begin with.
4) Dragon with Demolish Armor.
5) Capture his family/whatever few contacts are still talking to him, and kill them if he doesn't strip out of the armor. If he strips out of the armor, multiple long full bursts of SnS.
Honestly, though, take the player aside, tell him that the build is unbalancing the game, and give him the option of either reworking the character to not be obscene, or allow him to transfer Karma over to a new character, which you'll actually check over before blindly allowing it into the game.