Demon's Herald 
Creature — Human Wizard
,
, Sacrifice a blue creature, a black creature, and a red creature: Search your library for a card named Prince of Thralls, put it onto the battlefield, then shuffle.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL