Creature - Djinn 2/3, 1UU (3) You may choose not to untap Old Man of the Sea during your untap step. {T}: Gain control of target creature with power less than or equal to Old Man of the Sea's power for as long as Old Man of the Sea remains tapped and that creature's power remains less than or equal to Old Man of the Sea's power.1
Illus. Susan Van Camp
10/4/2004: You lose control of the creature if the Old Man leaves play. This is because it is no longer tapped.
10/4/2004: You do not lose control of a creature controlled by the Old Man even if you lose control of the Old Man itself, so long as the Old Man remains tapped. If player A taps an Old Man to control B's Old Man, and in response B taps to control A's Old Man, then the two Old Men switch sides. Now whoever untaps first will be getting both Old Men.