Serra, Angel Worshipper

When Serra, Angel Worshipper comes into play,
create a 4/4 Angel creature token with Flying.
{1}{w}{w}{t}: Tap an untapped creature you control,
exile target creature with power less than or equal
to the tapped creature's power.
When Serra, Angel Worshipper becomes the
target of a spell or ability, you may exile it, then
at the beginning of your next upkeep return it
to the battlefield transformed into Serra,
the Transcendent under its owner's control.