PSA: If a Youtube video is even marginally related to a show you're watching and you don't want to be spoiled, don't look at the comments. Especially don't click to the next page of the comments to find out what some person was replying to when they said something amusing. You just might find out about the existence of a future character you would much rather not have known about until said character's entrance. I don't know how Mark does it.
...It's a siggie