The Stand at Khazad-dun

Only legendary creatures can attack or block and
can only attack or block alone.
Sacrifice The Stand at Khazad-dun: Prevent all
damage that would be dealt to you and creatures
you control this turn.
"You can not pass! I am a Servant of the Secret Fire, Wielder of the Flame of Anor. The Dark Fire will not
avail you, Flame of Udun! Go back to the Shadow!"
— Gandalf the Grey