His ability to decern what Michael might do before he himself even knows. Leaves Michael between a rock and a hard place. He obviously isn't going to fall in line again with the guy that burned him just when he was getting back into the CIA. But Ansen is so good at his specialty and has so much background info that Michael has been unable to make even Tiny moves without Anson catching him.
Basically we are back to season 1+2 with Carla telling him to do what she says or else. And Michael knows it, and he's not gonna put up with it for a second. Except Ansen is smart enough to know that Michael knows etc.
Ansen has dug his way into Michael's head in a way that no villain before has. He knows everything about Michael and how he will act and seems to have him beat and Michael knows this. Yet in this episode he is forced to play the game and open his mind to Ansen (yay Beatrice!).
This is Extremely Dangerous for any Spy as they are trained to Compartmentalize things. And the really good ones (ala MW) do it as second nature. Plus people who haveDaddy Issues is a common recruiting element (MW again). When you start opening those doors it can be dangerous. Which is why Westen lies then changes the subject when Ansen questions his motivations about why he does the day-to-day client-taking thing.
I guess the only question left is will Ansen keep his promise that this has an ending. That he won't just keep dragging it out with one more thing the way it has always gone down before. If he's going to continue being smart then he should keep his promise and end it quickly.
Because it doesn't take a Super Shrink to know that after all he's been through since being Burned. Michael Westen isn't going to buy the, "it's almost over, just one more thing" line forever.
All in all, I'm actually happy to see a more cerebral battle especially since I suspect it is leading up to a big finish.
[Ever been to a summer popcorn flick and actually find yourself yawning at the predictable 3rd explosion? One explosion after another gets boring no matter how big the explosion; but if you build it up slowly then it really hits big even if the explosion itself was literally small.]