Arielia, Daughter of Phyluna

Changeling (This card has every creature type)
Whenever Arielia or another creature enters the battlefield or attacks, you may have Arielia become a copy of target creature except its name is Arielia, Daughter of Phyluna, it's legendary in addition to its other types, it has Changeling, this ability, and all abilities listed below.

{w/b}{w/b}: Return target creature card from your graveyard to your hand.