Nekroz Mirror

As an additional cost to cast this spell, reveal a
Nekroz creature in your hand that has Ritual.
You may sacrifice and/or discard any amount
of creatures whose converted mana cost
equals the revealed creature, then put the Ritual
creature onto the battlefield under your control.
If you control no creatures, you may exile this
card and one Nekroz creature in your graveyard,
then search your library for a sorcery, reveal it,
put it in your hand, then shuffle your library.
Limited 3