Sarah Kerrigan, The Ghost

Spiritual Leader — At the beginning of combat
on your turn, put a +1/+1 counter on target
creature.
Psychic Stimulus — : {t}Add {c}{c} . When you
next cast a spell with {x} in its mana cost
or activatean ability with {x} in its activation cost
this turn, copy that spell or ability.
You may choose new targets for the copy.
(A copy of a permanent spell becomes a token.)