Gideon, Legion Assembler

+1: Until end of turn, target creature you control gets +1/+1 and gains mentor.
0: Until end of turn, Gideon, Legion Assembler becomes a 4/4 Human Soldier with indestructible, shroud, and mentor that's still a planeswalker.
-3: Until end of turn, whenever a creature you control attacks, put a +1/+1 counter on that creature.