[Entity]

Well, you already know my thoughts, but it's misleading to call him a maniac in the title. You've told everyone here that he's slowed down AFAYK when you've responded with aggression and it's not like he put in 4 bets on the flop, 3 on the turn and 2 on the river with AT on a QT882 board.

His move is generally a sign of uberstrength. It could be a big draw (JTh) but seems more like a turned better hand unless you think he's a bluff bet-caller bluff checkraiser bluff river bettor (into two opponents).

I'd be interested if anyone thought about what range of hands he is going to be having in a situation like this.