
The "legend rule" doesn't apply.
Mirror Gallery has 2 printings, first in Betrayers of Kamigawa (2005). EDHREC ranks it #8,104 among Commander cards. It appears most in Deadpool, Trading Card decks (3,579 on EDHREC). It has 1 official ruling.
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.