Instill Energy

{G} · Enchantment — Aura

Enchant creature Enchanted creature can attack as though it had haste. {0}: Untap enchanted creature. Activate only during your turn and only once each turn.

Motor: se resuelve a mano

Rulings (3)

Any Auras (or other effects) which are on the creature that would cause it to not be untapped (or have a cost to be untapped) during untap step do not in any way hinder or imply a cost to use this card's ability to untap once during the turn.
Wizards of the Coast · 2005-08-01
If attached to an opponent's creature, you can untap their creature during your turn.
Wizards of the Coast · 2004-10-04
Instill Energy's untap ability will not untap the creature until it resolves. This means other spells and abilities can be used before it actually becomes untapped.
Wizards of the Coast · 2004-10-04