User blog comment:OneFilthyHobbit/Move stealing Champ plz/@comment-7007348-20130410070712

Think about TF, Pantheon, Karthus and you'll see a pretty good reason why NOT to have a champ that can do that.

Having two champions with the same abilities on the same team would be a bit problematic, and some abilities are so worthless it's not worth doing anyways.