1 Dec 2004
“Unattach Heartseeker” means just that — Heartseeker moves off the creature it was equipping and remains on the battlefield.
1 Dec 2004
Heartseeker grants an ability to the equipped creature. The ability can target a creature with protection from artifacts (unless the equipped creature is an artifact creature).
1 Dec 2004
The equipped creature’s controller chooses whether or not to activate the activated ability. It doesn’t matter who controls Heartseeker.