So I've been thinking about Undertale classpects a lot recently, and I'm personally of the opinion that Sans and Papyrus are a Page of Doom and a Knight of Heart or Blood. Sans is the perfect Page - allowing others to Serve him through his own depression-induced pessimism. Also there's the bit about how the Doom-bound are the universe's chosen sufferers - that's Sans right there. He even does the page thing where he's basically useless until someone makes him get off his ass. 1/2

2/2 And then there’s Papyrus as a Knight of Heart or Blood. He’s got all the traits of a Knight - he puts up a happy “look at all the friends I have” front, and is constantly serving others by trying to help them maintain or form relationships. Heck, he only dates you because you flirt with him and he doesn’t want to make you upset. Both Blood and Heart have been connected to relationships, but I’m leaning more towards Blood just because the Extended Zodiac says the Heart-bound are self-centered

I do agree Papyrus is kinda Knight-ish, so that’d fit- However I can’t quite see Sans as a Page. Mainly because, that sort of depressive pessimist attitude of his doesn’t seem like something he puts up to get help. He’s a bit of a loner when it comes to his suffering, having people Serve him anything would only make him queasy. That’s my opinion at least.