An Interesting Evening.
I played about 2 hours at a $5/10 table last night. I saw a big phat donk I had played against before was already seated with $500, and I had my choice of a seat immediately on his right, betting into him, or three to his left, with two players between us. I reflexively chose the seat three to his left, but in hindsight I should have taken the one to his right. He plays nearly maniacally pre-flop and his habitual three-bets would have been great for getting him isolated HU. The seat I took was still good, as the two donks between us turned out to be serial cold-callers.
I plopped down with $250 and went to work. He rivered me twice in the first two orbits, and I was down 17.5 BB. My head was spinning, as this was taking me from having a net positive month to date to being in the red - again. I sat out a hand, took a few deep breaths and analyzed the situation at the table. It doesn't matter what I did yesterday, or so far this month. It doesn't matter that mega-donk is up $150 on my money. What mattered was that he was a huge fish, I had position on him, there were other fish at the table, I have excess bankroll out the ying-yang to play $5/10 - this was a premium situation. That's what mattered. That's all that mattered. I reloaded to $250 and went back to work.
Donkzilla continued to raise or re-raise nearly every hand pre-flop. He three-bet 86o and T3o. His stack fluctuated wildly, and I noted that when it got below $300 he started limping in. He was still seeing 95% of the flops, but his hyper-aggression cooled. Until he got below $200, then he went into overdrive again. Back above $200, he limped. Back above $300, overdrive. He became very predictable in that regard.
His post-flop play was less bad than his pre-flop play. Not good, but less bad. He could not let it go if he caught any piece of the flop. This included any draws to 4 outs or better.
I called for one more with K6s from the BB with just 3 players in the pot because the implied odds were so good with him. I rivered the nut flush and he felt compelled to show me that he had cold-called a PFR from the cutoff with A5o. Having flopped his A, I guess he felt screwed.
I picked up a small pot when my pair of TT saw a KQX flop. It checked around and I picked up a J on the turn and a 9 on the river for a crappy straight. Megadonk had slow-played a flopped top-two pair. He was now below $200 and betting wildly pre-flop and flop, throttling back on the turn if he had nothing. Some other guys did a little feeding off him while I waited for cards.
With about $75 left he raised two limpers into me as I was sitting on the BTN with KK. I 3-bet and got a call and a fold. He capped and we both called. The flop was 678 two-suited. He bet and I raised, folding the other guy. He 3-bet and I capped. He called. Turn is another 8. I am not liking this board at all, but he could literally have anything - anything! He bet and I raised. He called. There it was - the slowdown I wanted from him. River is a T, making 3 for a flush as well. An awful card for me. But he had slowed down on the turn, which meant he had nothing. Not even a good draw. He might be sitting on 32o for all I knew. He checked and I bet. With 16+ BB in the pot, and 1.5 left in front of him, he folded for one more bet. 
That put me up about $70 for the session. He donked his last $15 off on the next hand and left the table $500 lighter than he had sat down with 2 hours earlier. I checked off the table before posting the next blind.
I made a lot of good choices last night. That does not always pay off in poker, but last night it did, and it felt very good. 