100NL, DB blufff on a tricky river

villian is running 18/14/1.8 over 350 hands with 34% ATS. His fold to 3 bet% is insanely high like 89%. Also, i noticed that his 4bet% is 0% out of 9 chances. So i 3 bet this fellow with shit and expected him to fold the majority of his stealing range in this 7-handed table. Of course I would go 1/2 pot on flop and a little more than 1/2 pot bet on the turn with my entire value range on king high board. After he called twice and bet like ass hole on river, i could only put him on AK or some unlikely slowplayed sets & flush really.
No-Limit Hold'em, $1.00 BB (7 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

Button ($100)
SB ($102)
Hero (BB) ($100)
UTG ($119.05)
MP1 ($124.75)
MP2 ($100)
CO ($100)

Preflop: Hero is BB with 4, A
2 folds, MP2 bets $3, 3 folds, Hero raises $9, MP2 calls $7

Flop: ($20.50) K, 7, 6 (2 players)
Hero bets $12, MP2 calls $12

Turn: ($44.50) 9 (2 players)
Hero bets $25, MP2 calls $25

River: ($94.50) A (2 players)
Hero checks, MP2 bets $6, Hero ?

I fold this pre, 3bet something else.

just call the river, or like, click it back ahahaha

preflop is pretty spewy since he's only been 3bet 9 times, that's nowhere near enough of a sample to say that he folds to 3bets too much. For sure I would have SCs and suited aces in my range in this spot but I think A4o is a bit silly.

Flop cbet is alright. If you think hes folding to that many three bets and never 4betting (which you can't assume over this smaple but you have done so this is just following though with your logic) then you should just c/f. I actually like the cbet because I doubt he is folding to that many 3bets, but for preflop to be good the flop should be a c/f

Turn: I guess you get him to fold QQ/JJ but they fold flop sometimes and call turn sometimes so it's by no means a sure thing. He only need to fold ~1/3 of the time for this to be good though so I think it's just about ok.

River, I like the check, now I call because fuck you that's why. We're very rarely good but getting this price I can't fold even though I can't really name a single hand we beat. Meh.