Roshan, Hidden Magister
From Assassin's Creed set
Roshan, Hidden Magister
Legendary Creature — Human Assassin
4/4
Other creatures you control are Assassins in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
Face-down creatures you control have menace.
Whenever a permanent you control is turned face up, you draw a card and you lose 1 life.
Rulings
- Once a creature you control has become blocked by a single creature, giving it menace by turning it face down somehow won’t cause it to become unblocked.