Junko, Ultimate Fashionista

When Junko, Ultimate Fashionista enters the
battlefield, gain control of target creature until
the end of turn. Untap it. It gains haste until
the end of the turn.
{1}, Sacrifice another creature: That
creature's owner gets a despair counter.
At the end of beginning of each end step,
if you have one or more despair counters,
transform Junko, Ultimate Fashionista