Ari Vehn, the Conflicted

First strike, lifelink
Manashift {5}{w}{w} (You may cast this spell for its manashift cost. If you do, it becomes white and loses
all other colors.)
As long as Ari Vehn is white, it gets +1/+1 and
has "{2}{w}, {t}: Destroy target black creature." As
long as Ari Vehn is black, it has "Sacrifice a
creature: Target creature gets -1/-1 until end of
turn."