Lelouch's Absolute Obedience yet to the point where i can use it on a person multiple times provided i dispel my Geass afterwards (so say i ordered someone to get me a drink, i can use my Geass on them again but say i did what Lelouch did to Shirley to rewrite her memories, she would be under the control of Geass constently so i couldn't use it on her again till i removed it's control and she would remember)
The catch, it would get out of my control Like Lelouch but since i can dispel it i can't joke around (so say that i said "Oh go f**** yourself", they would do it so i could have to dispell the Geass before they started)
Now for the spoiler, simple, DARK SHADOW AURA! i'll be naked but no one could see my body because of the aura, they could still see my eyes though