Grunch:

Unless this guy is a total nut job there are only 5 realistic flushes he can have (K9-T9cc). I don't think he's bluffing given how much strength we've shown. The question is he over valuing a worse two pair hand? Has he lol slowplayed a set?

I call, but it's not a fist pump call.

Edit: I agree with the others, shipping is pretty bad. I don't think worse will call and I don't think turning your hand into a bluff is a good idea either.

No, not everyone. I specifically said that the only 2-pair hand I see in his range is a couple of combos of A8.

Grunching ...

Based on your descript he could be betting the scare card with > PSB. Could also have 98 and putting you on a big ace with your line. Either way, he is not calling with those and probably not others that are behind.

Call.

I'd rather fold than shove TBH.

I'm having a hard time finding a range you can profitably call, much less shove. We expect villain to know the river isn't a good bluff card because it's hard to sell runner,runner straight/flush to a thinking opponent. We expect V to c/r with two pair and sets on the turn. K9cc - 98cc make sense as does 76ss. I think V checks the river with top pair. We block Axs of spades. I don't think V calls two streets with A5s.

This seems like one hell of a double float bluff or a hand that beats top two. I'd probably still call because I would also expect villain to c/r with draws on the turn. Tough spot.

I think V with this description treats all 2 pair combos as the nuts on this board. He can believe that he coolered your AK or AQ that you would play the same way. This V also likely has many 2 pair combos being sticky and wide preflop and postflop.

I definitely think you are missing value not shoving the river. I don't think V folds any 2 pair combos when you shove on the river once he has committed soo much. Another way to think about this spot is that if you think A9 is at least a call and AK is a fold then you should probably be value raising A9. He can't have 2 pair when you have AK and suddenly not when you have A9. He doesn't have a ton of value combos that beat you and you only have to be good >50% when called.

Closer to a fold than a ship.

Ok. if giving him one combo of A8, why would villain play A8 passively on a double flush draw board on turn but you would expect him not to play his set of 4s the same way? The profile and ranging of villain are very contradictory. As I said, if anyone is giving him a range of 2pair, then you almost have to include set of 4s, as the two hand types play very similar (either fast or decpetive/trappy/weak tight)

I just don't see any inferior value hands to our's and his bluffs shut down once we shove. We basically have a bluff catcher.

Yeah i've noticed that people lead/donk rivers unbalanced a lot. But i don't think OP can have the Nuts/Flush here often enough in this spot either.

The problem with shipping is that all bluffs fold(obvi),all better hands snap and not all two pair combos call,river is a call.

I can see one combo of A8 (maybe 2) in his range because he'd likely call the c-bet with it to eval, and would occasionally (but not often at all) flat the turn, just because Hero's sizing tells him Hero is not on a FD.

44 would have to flat with a strong, but vulnerable hand twice, much less likely than the (still not very likely) turn only required for A8.

That said, I agree with your bottom line, and have from the get-go.

Results

If villain is the sort who won't slowplay on the turn, his range is usually polarized between bluffs and hands that improved on the river. You beat A5 and 54 and lose to straights and flushes. While he might fold a straight to a raise, it is a lot less likely that he calls a raise with two pair.