Magnetic Mountain [Revised Edition]

Set:	Revised Edition
Type:	Enchantment
Rarity:	Rare
Cost:	{1}{R}{R}

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.