Avia, Nimble Master

Flying, haste
{w}, {t}: Put a restraint counter on target creature
you control. That creature gains protection from
the color of your choice until end of turn.
(Creatures with restraint counters have defender.)
{1}{u/r}: Release. (Remove a counter from target
creature. If you do, it gets +1/+1 and gains flying
until end of turn. Activate only as a sorcery.)