Ren, The Ever-Loyal

+1: Target creature you control gets +2/+1 and vigilance until end of turn
-2: Ren, The Ever-Loyal becomes an X/X Shadow Knight until end of turn where X is the highest power among creatures you control.
-15: You get an emblem with "Creatures you control have +3/+2, Haste, Vigilance, Double Strike, and Trample"