Necrozma

Reconfigure to Legendary Creature {2}{u}{u}
Equipped creature has +2/+2 and "Whenever
this creature deals combat damage to a player,
that player becomes Necrozma's Host".
During your upkeep, if you have ten or more
cards in hand and Necrozma is attached, you may
Unite Necrozma and the equipped creature.
Partner with Necrozma, Dusk Mane or
Necrozma, Dawn Wings