If Rammus has too much movement speed he will sometimes travel through units when in Powerball.

I dont know the magic number for him to do it but you need to be in Powerball with home guards, the movement speed effect of deadmans plate, and the active of Righteous Glory. He tends to go super fast, so fast that i've gone through a champions a few times and minons. Had to go back to hit them. Really annoying.