Maniacs make me into a donk

[PokrLikeItsProse]

I come from a limit background where playing against a maniac often involves waving a red cape in front of the maniac and encouraging him to charge at you as you call him down.

Since you appear to be talking about no limit (which is not my area of expertise), you should probably play in such a way that you get more heads-up pots. Hands that don't need much improvement to win, such as two big cards go up in value, while things like suited connectors go down (if you are successfully isolating the maniac) because maniacs are sometimes unbluffable and you can't successfully semibluff your draws if your chances of bluffing are nil. You could also be making the mistake of raising too often and by too much pre-flop. There are other players in the game. Just because a maniac is playing every hand, that doesn't mean that you should start playing your top 50% of hands on the assumption that your hand is, on average, better than his. It actually makes sense to tighten up pre-flop in no-limit hold em against a maniac.

If he is a true maniac who will make a three-bet bluff, then you are going to play much more aggressively and be willing to stack off with top pair middle kicker against some of them, but if he is really just a habitual bluffer who slows down if he encounters pressure, but who likes to bet or raise on scare cards, then you are going to do a lot more trapping and check-calling. Against the former, drawing hands are poor, while a pocket pair is something you might hold onto against multiple bets with overcards on the board. Against the latter, you probably make a decent chunk of your money by snapping off big river bluffs.