The Pocketcat

This creature is Black.
{t}, Sacrifice 3 Legendary creatures: Search your library for a card. Put it into your hand then shuffle your library.
{t}: Target opponent chooses a Legendary creature or planeswalker to sacrifice.
If they can't, they lose half of their life (rounded up)
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"A servant of the trickster god – the Moon. His motivations lie in the path laid out by the older god."