Guide of Souls 29/303 (Modern Horizons 3)

Whenever another creature you control enters, you gain 1 life and get {E} (an energy counter). Whenever you attack, you may pay {E}{E}{E}. When you do, put two +1/+1 counters and a flying counter on target attacking creature. It becomes an Angel in addition to its other types.

NM - $2.90
LP - $2.30
MP - $1.80
HP - $1.50
DMG - $1.50