I think he got 2 new abilities. The first one is that emotion control voice thing. But the second is possibly detecting abilities. What I mean is by touch he can detect abilities (or lack there of). On pg 655,672 and 674 if unlocked it mentions the each of the diznee triplets touch feeling either cold, empty or squishy. It also mentions Kelser feeling empty like one of the triplets which leads me to believe he sensed that Kessler is talentless (as we already know) and that one of the triplets would be talentless one would be a froster and one would be… I have no idea what squishy could be.
Well, I think that Keene is a Mesmer, but he affects the heart AND the brain. I also think that Keene has a new kind of ability detector. when he touched the tree triplets, one of them was probably talentless, the other one felt cold, so he was probably a Forster, and the one with the squishy hand is probably a phaser.