
Blue creatures don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player may choose any number of tapped blue creatures they control and pay {4} for each creature chosen this way. If the player does, untap those creatures.
Magnetic Mountain has 6 printings, first in Arabian Nights (1993). EDHREC ranks it #23,458 among Commander cards. It appears most in Akroma, Angel of Fury decks (16 on EDHREC).
Deck counts from EDHREC.
Cards that show up in the same decks on EDHREC.