I struggle at Full Tilt and here's an example why. Any suggestions?

Villain is 25/19/3.5. He's super aggressive on the flop AND turn. He's fully stacked.

Villain raises 8[d] 8[h] to 6 (x3bb). A TAG reraises him to 21 and he calls.

Flop ($42) 5[c] 4[s] 2[d]. Villain cks, TAG CBs a weak $24. Now Villain min CRs to 48 and TAG somehow calls.

Turn ($150). 9[d]. Villain now leads $75. TAG calls and the check the river. Villain loses to TAG's TT.

I think both of them terribly misplayed their hands, but how do I play against Villain when he plays a small overpair like a set? FTP is full of these guys. Do I just go into rock mode (boring!)? Do you felt with JJ there because Villain's pfr was only x3bb so you're just felting no matter what?

Why do you think that TAG misplyed his hand?
IMO TAG played this hand good. I would play it the same, though if I thought that OP is full of it I'd 3 bet flop.

Villian's line doesn't look like a set, mosts sets c/c flop and c/r turn (stack-a-donk line).
His line flop raise is: 'Would you please lay down your AK?', on the turn he thinks that OP is likely has a pair but decides to throw a weak bet just to be sure.
(If villian pushed river or made a big bet on the river I could lay it down, but players who could bluff like that are rare. Moreover I wouldn't lay AA, KK, so this play wouldn't be +EV for him. )

IMO with a good read on this villian one could VB river here after a river check.