500k damage?

It's a known bug that Yorick can do over 400k damage with his ult

It is a completely normal interaction of Yoricks ult. The resurrected spirit of a champion takes 100k true damage at the end of the ult duration to make sure that this champion stays dead. But what is not intended is this damage to show up in the damage graph. By this you can deduce that he ulted the Kindred once and himself 5 times.