We were both 300bb deep and the villain is 20.5/18.6 pfr, 3bets 7%, seems somewhat positionally aware, raises more from late position than early. All indications of a typical probably winning tag. We've had no history with one another at the time, I was playing 22/17 3betting at 8%. I've had about 250 hands on my opponent at the time of the first hand and did not have any evidence that he was or is prone to getting out of line.
Party Poker $100.00 No Limit Hold'em - 4 players
The Official DeucesCracked.com Hand History Converter

BB: $371.10
CO: $93.50
Hero (BTN): $293.45
SB: $131.90

Pre Flop: ($1.50) Hero is BTN with A A
1 fold, Hero raises to $4, 1 fold, BB raises to $12, Hero raises to $29, BB calls $17

Flop: ($58.50) 4 Q J (2 players)
BB bets $26.00, Hero calls $26

Turn: ($110.50) 4 (2 players)
BB bets $58.00, Hero folds

Final Pot: $110.50
BB wins $50.50
BB wins $58.00
(Rake: $2.00)

I know I probably under represented my hand postflop but I think the flop smacks right into his 4bet calling range. Less than 20 hands later villain did this.

Party Poker $100.00 No Limit Hold'em - 5 players
The Official DeucesCracked.com Hand History Converter

BTN: $383.20
SB: $75.55
BB: $100.20
Hero (UTG): $293.45
CO: $148.25

Pre Flop: ($1.50) Hero is UTG with K A
Hero raises to $4, 1 fold, BTN raises to $13, 2 folds, Hero raises to $38, BTN calls $25

Flop: ($77.50) 8 5 Q (2 players)
Hero bets $55.00, BTN calls $55

Turn: ($187.50) J (2 players)
Hero checks, BTN checks

River: ($187.50) K (2 players)
Hero checks, BTN bets $120.00, Hero calls $120

Final Pot: $427.50
BTN shows 7 6
Hero shows K A
Hero wins $425.50
(Rake: $2.00)

I called here because I think he would've put in multiple streets of value had he hit jj qq on this board. I thought about him completing with AT on the river and was making a 2/3rd pot value bet. It may have been a factor that I played the AA hand so weak, and that I felt this guy was just trying to run me over or thinks that I'm scared money deepstacked.

It was a surprise to me that he called my 4bet with 67suited though, which led me to wonder if I induced the bluff by playing that first hand so weak, which would be fine. But also made me wonder if I made a terrible fold with the AA hand, now that I know that he was 3betting me and calling my 4bets pretty light. What could I have done to play either hand better? Was it possible for me to not give him as much credit as I did with the first hand, w/o seeing that he was capable of 3betting light and then calling my 4bet so light.
Sorry such a long post, first time posting.