Overall, The Mechanist feels like an upgrade to Sai, Master Thopterist
Whenever one or more other Cats you control die, you may exile Ajani, then return him to the battlefield transformed under his owner's control
No two symbols from different sets are the same to prevent confusion
Finally, it tells me that the format itself is in a pretty sweet spot
Creatures (18) 4 Hangarback Walker 2 Ulamog, the Ceaseless Hunger 2 Kozilek, the Great Distortion 2 Reality Smasher 4 Thought-Knot Seer 4 Matter Reshaper Planeswalkers (4) Lands (28) Spells (10) As you can see, were really not getting all that much compared to just playing green or whatever
Back now to another major part of what makes Jace the best planeswalker outside of cube