I’ve been getting this question a lot as well, so I’ll answer it here so you guys can see. (Get ready, cause this is going to be a LONG devlog post.)

The reason that Sans is going to be in Undertale Purple, but Papyrus isn’t is because, like many people, I believe that Sans is the older brother of the skelebros. However, I also believe that Sans is actually extremely old, and I believe this because:

Sans knows that he goes through each timeline reset that Flowey performs, but he doesn’t retain his memories when the timeline resets. Technically, although the timeline itself is the thing being reset, I believe that this means that Sans does still age as he goes through the resets, but doesn’t age at the same time. (I know, it’s confusing, but some people will know what I’m talking about)

Because of this, I think Sans is extremely old, but he doesn’t look, sound or act like it because he goes through the resets, that turns back time, but at the same time, he’s still conscious of this. So…summing it all up, he ages, but not in the way of actual aging. (It’s confusing, but hopefully you can see my logic here)

Basically, what I mean by this is that Sans could have been born at any point during the 6 human souls’ adventures, because of this theory of mine. Therefore, I think it makes sense that Sans would be alive at this point in the Undertale story.

Papyrus, however, is just like everybody else. When the timeline resets, everything about him resets too. (Age, memories, everything) If you were to ask me how old I think Papyrus is, I’d have to take a wild guess and say he’s probably somewhere from early to mid twenties.

Now, let’s say that the time between each human falling into the Underground is 8 years. Chara comes, dies. 8 years later, the cyan soul comes and dies, 8 years later, the orange soul comes and dies, and the cycle repeats until Frisk falls. Now, 7 humans came before Frisk, so if there were truly 8 years between each human, then that means that at the time of Genus’ arrival, it would’ve been 32 years since Chara came. Genus dies, then there are two others after Genus before Frisk. This means that when Frisk comes, it’ s been 24 years since Genus came. So, if Papyus is, say 21, then that means that he is born between the time that Genus dies, and May (the green soul) arrives. This means that Papyrus, according to my theory, can definitely be in UTG, but not UTP.

So there you have it. An explanation that was probably way longer than it had to be. I’m really sorry if you read all that and were bored, I just needed to explain it in full detail.

Thanks!

— 3JAD21, Main Dev