100nl, AK preflop vs drunk donk

Pokerroom 100nl, about 2 or 3 am

Full ring game, but has become short handed to 5 players. Villain claims to be drinking, which I dont doubt, and has raised 75% of all pots preflop. Sometimes to 25 bb with noone even in. Another person called his 20bb raise and Villain ends up showing 55. I think I might have ticked him off by taking a big pot off of him a few hands ago, then this hand comes...

villain has 90, hero covers

preflop
UTG villain calls, MP raises to 2, hero in LP raises to 6 with offsuit AK, sb folds, bb folds, Villain raises to 30, MP folds, hero???