Yorick's Ult

I don't have any video evidence, but this Gyazo might give some perspective, it appears that Yorick's ult ending is adding to his damage to champions. While in a game with a Yorick ally, when it wore off, I noticed the damage on me was 100000. The attached Gyazo is not mine, an enemy was kind enough to send it to me. I also think it is possible that his ult ending is adding to the ally's damage whom he ulted. If this is the wrong place to post this sorry.