I like this idea.

shyvana breathes fire into the air, ooh maybe she could descend down in dragon form and emerge from a fireball as human form kneeling like she braced for impact
galio reanimates from his stone form.
lux becomes tangible after flashing in from a ball of light/some kind of sparkling light effect.
vayne tumbles in large cross bow drawn
fiora could do a very fast series of practice jabs followed by a diagonal downward slash

and while u are at it, make 3d portraits so we no longer watch for 40 min the same picture

I don't like this idea.

Not because I don't like the idea of summon animations when the games start... but because as long as the quarter-screen bug keeps rearing its ugly head, I'll miss the animations when alt-tabbing to resolve the bug.