Demon Parade

Whenever Demon Parade attacks, exile the top
card of your library. If it's a Demon or Devil
creature card, put it onto the battlefield under
your control tapped and attacking. At the
beginning of the next end step, sacrifice it and
put a +1/+1 counter on Demon Parade.
Otherwise, if it's a nonland card with mana value
less than or equal to Demon Parade's power,
until end of turn, you may cast it from exile
without paying its mana cost. When you do, put
a -1/-1 counter on Demon Parade.