I 'm siting at a table with mister As He plays only As. I, however, plays Nash optimal. We HU.

Now I'm stealing all his blinds and he folds all my bigs. Sometimes, he calls my bet or he 2bets my bb.

In this particular hand, he's calling my bet. My hand is KQs. Comes the flop: KhTd9h. I cbet the pot. He calls. Turn is 2s. I bet the turn. He calls. River is 3s. I bet. He calls.

What tells me that stealing his blinds generated more money that what I just lost? More precisely,.. yeah I could count, but what tells we can't find a bot similar to mister As for which playing nash-optimal is -EV, using the same idea?

Or more directly: do I need to include my opponent range to execute an approximation of the absolute best strategy (because the best strategy would include the use of the opponent perceived range)?

How much did you lose in the AA hand? Because you'll make a lot from his blinds.

He'll have AA 1 in 221 hands. Let's say he wins an average of X from those hands. The other 220 times, he will lose an average of .75bb

EV = -X/221 + 220/221*.75
220*EV = -X + 220*.75
now, to find the breakeven point, set EV=0
0 = -X + 220*.75
X = 220*.75 = 165

I don't think any NE strategy is losing 165bb per hand that he has aces.

Anyway, the literal definition of a NE is when neither player can gain an advantage over the other by changing their strategy. If some weird strategy is not an NE, then it can not be better than an NE, because if it was, you could improve by switching. It's by definition non-sensical.