Grimoire of the Mindless Legendary Artifact At the beginning of your upkeep, if you control a Zombie, you may put a study counter on Grimoire of the Mindless. , Sacrifice Grimoire of the Mindless: Put the top X cards of your library into your graveyard, then search your library for an instant or sorcery with converted mana cost X or less and cast it without paying its cost, where X is equal to the number of study counters on Grimoire of the Mindless.
I was fiddling around with Grimoire of the Dead and wanted another big 'ol zombie book for my zombie-mill. This would be fun to search for, say, Traumatize , or even just a Mana Leak when they try to cast something. The only prblem is i could see it being broken if it allows you to cast sorceries at instant speed, which im still trying to figure out if it actually does or not.