5 handed, game is decent, one big whale who is main vilain in this hand

New player 200$ co posts Big blind
Whale 2.8k on btn raises to 20$, whale is vpiping about close to 100% and raising when it gets to him about 80%.

I'm in SB (600$) with AAQ96

I Just call, I've been 3betting the whale a ton, only in position, I wanted to play a bit less variance out of position since he calls any 5 and being out of position sucks.
New player calls the 20$

Flop (66$)
A96

I check, new player checks, whale checks. Whale has been cbetting almost everytime and betting almost any draw, which is another reason why I called pre since my edge post flop is massive vs him.

Turn (66$)

A96 3

I check again, new player checks, whale bets 66$, I repot to 264$, new player folds. Whale tanks and calls.

River (594$)

A963 7

Hero has about 1/2 psb left and?? whale is bad enough to call with a set, maybe some 2pair (but I block alot of those), but he mostly has draws imo even if i block diamonds. I havent seen him bluff huge but I feel like this is a must bluff spot for him if I check...really not sure what to do here. I shouldve just 3bet pre haha

The fact that you've been 3 betting him a lot would make me want to 3 bet him here for sure. You don't have to bet the flop just because you 3 bet him.

Whales generally don't tank call with sets, so is he really going to call with aces up or 9s and 7s? Seems like you should let him bluff at it to me.

I understand flatting pre simply because most people play 3bp OOP as pfr very poorly, but this hand is a clear enough 3b that I think you're better off trying to fix that problem than flatting it.

Of course 5c PLO you definitely do flat AA OOP at this stack depth.

Flop seems good. If it were deeper even x/calling could be correct if it's someone who barrels.

Turn I like the check raise. Perfect.

I think blocking diamonds, I would probably just x/f. If you had a straight blocker and fewer set/2p blockers jamming is not too bad. You just really block anything that isn't a straight draw. Also some of the sets just jam turn and that's another thing that removes combos of hands you beat from their range.

Like, it's hard to even find a hand they have that bricked, and people don't turn sets or two pairs into bluffs much.

In 5 card especially, you really have to fold strong hands if you don't beat anything.