Thoughtbane Triplet

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Thoughtbane Triplet deals combat damage to a Player, Fateseal 3, targeting that Player. Then you may have that Player put the top card of his or her libarary into his or her graveyard. If you don't, that Player discards a card at random.
The sickness they spread is of the mind.