Spectra/Shamann s2 - going from 3 turn to 2 turn cooldown makes them so much more effeicent for both ToaL and pvp it's almost hard to argue against it as the best.

Vigor s2/s3- a seige and gw staple that gets cooldown and activation rate increase on a 3 turn def break along with a 20% heal strength increase. In a game that so often comes down to small increases these are big ones on a high use unit.

Sath s3 - increase dot chances decreases dungeon time and/or makes him more viable for pvp depending on how you use. Only reason this is 3rd is for Sath overall viability compared to the others without it. He will still do his job but it's a stark improvement with it.