Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Sacrifice a creature: Regenerate Dimir House Guard.
Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same converted mana cost as this card, reveal it, and put it into your hand. Then shuffle your library. Transmute only as a sorcery.)