
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 {U} for each creature chosen this way. If the player does, untap those creatures.
Thelon's Curse has 1 printing, first in Fallen Empires (1994). EDHREC ranks it #32,255 among Commander cards.
Cards that show up in the same decks on EDHREC.