River play vs pot donk bet

Wow what a super sick river.

I like how you played this hand.

The guy is either sandbagging quads or he just hit kings full on the river. I am not sure he would do this with a weak flush though it's possible he might with busted straight draw on the turn.

Either way I think it's a fold for me.

Hero's hand is somewhat face up there. Overpair or air. As villain is an aggressive, one can level himself for calling. Villain knows that hero doesn't have full house there almost ever, as the only hand for that is KKxx.

If villain has a flush, I think he would have bet smaller to get a call from aces. But if someone calls the turn with almost air and then donks full pot there on the river it surely looks super strong. Would opponent do that as a bluff often enough? Without reads I would fold too, to make the call you really need some proof that villain is capable of doing that.