Oh, man, my youngest dd loves sharpies, and dh has a bunch

She's sharpied my new(then) couchs--2x, the kitchen linoleum, walls, herself, you name it
Magic eraser worked on the floor, but not on the walls. I think the only thing that worked on the walls was painting. Dh just pained over with several coats until it didnt' show through. It didn't take that many coats for us though.
Good luck. I feel your pain.
Love, Carey