TPNK vs possibly tilting lag. River value question

[deaders]

This guy was 35/20/5, very aggro and Im not sure if hes on tilt or just a donk. Earlier in the session he bluff c/red all-in with 3rd pair vs my made straight. Ive been very aggro at the table but only shown down solid hands, 25/20/4.

Preflop: Hero is CO with A[img]/images/graemlins/diamond.gif[/img]5[img]/images/graemlins/diamond.gif[/img]

Folded to me, Hero raises $7, SB calls.

Flop ($16): A[img]/images/graemlins/spade.gif[/img] J[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/diamond.gif[/img]

SB checks, Hero bets $12, SB raises to $35, Hero calls.

Turn ($86): 7[img]/images/graemlins/diamond.gif[/img]

Check, check.

River ($86): Q[img]/images/graemlins/spade.gif[/img]

SB checks, Hero...

He will bluff raise this flop very often imo. Value in betting river, and what size? How do we respond to a c/r vs this guy?