i disagree on ilyana being among the worst units in the game. her growths are average at worst, her caps are good, and her good skill makes up for thunders low hit. granted she isnt my absolute fav magic unit (which would be laura) she is far from worst and she is one of the only mages with a good defense growth and decent hp growth. also her speed growth is about the same as sorens, and if you give her decent lvls she wont be that under lvled in act 3.
anyway my picks would have to be meg( what good is a tank that cant tank?), fiona( literally no opportunity to use her effectively, shame too as her growths are decent) most laguz who arent fliers, leo, and sothe who i never could get to be useful