Altar of Bone

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card, reveal it, put it into your hand, then shuffle.

Academy Rector

When Academy Rector dies, you may exile it. If you do, search your library for an enchantment card, put that card onto the battlefield, then shuffle.

Academy Researchers

When Academy Researchers enters the battlefield, you may put an Aura card from your hand onto the battlefield attached to Academy Researchers.