Oni's Gift
Swordmage Utility 22
Like the oni of children's fairy tales, you can disappear from view until you are ready to strike.
Personal
Effect: You are invisible until the start of your next turn or until you attack.
Sustain minor: You stay invisible or, if you are no long invisible because you attacked, you become invisible again.
Oni's Gift is a daily power available to swordmages at the 22nd level.[AP:61]