The Changeling

Cannel (Whenever you make an opponent put a card
from there library into their graveyard deal 1 damage
to target permanent. You may deal damage in this
way up to the number of permanents that you control
with channel each turn. )
If a spell or ability other than The Changeling
would make an opponent put a card from their
library into their graveyard, have that player put
the top card of their library into their
graveyard.