Gauntlet of Power
Artifact
As this artifact enters, choose a color.
Creatures of the chosen color get +1/+1.
Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.
Greg Hildebrandt
Dominaria Remastered (DMR)
• #223Rulings
Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a creature of the chosen color may become lethal if Gauntlet of Power leaves the battlefield during that turn.
(wotc • 2022-12-08)
If Gauntlet of Power is somehow on the battlefield with no color chosen for its first ability, no creatures get +1/+1 and its last ability never triggers. It still won't affect colorless creatures or basic lands tapped for colorless mana.
(wotc • 2022-12-08)
Rulings
Because damage remains marked on a creature until the damage is removed as the turn ends, nonlethal damage dealt to a creature of the chosen color may become lethal if Gauntlet of Power leaves the battlefield during that turn.
(wotc • 2022-12-08)
If Gauntlet of Power is somehow on the battlefield with no color chosen for its first ability, no creatures get +1/+1 and its last ability never triggers. It still won't affect colorless creatures or basic lands tapped for colorless mana.
(wotc • 2022-12-08)