So Gaster is an amalgamate because he injected himself determination, right? Okay.
So now that we know that Gaster is a skeleton (wait what no you didn't say that) and that he was split in two, he was obviously split into Papyrus and Sans. Here, I'm gonna explain this to you through evidences I guarantee you've never heard before.
- cue evidences we've already seen and also i have already used in my previous video to prove something opposite of what i'm proving right now, therefore making these evidences weightless -
Okay so now that we know that Gaster was split into Sans and Papyrus, we could also dig deeper and, oh look, Gaster was obviously talking to Sans and Alphys in his entries, it all makes sense.
"Dear half of me that doesn't exist yet and that I have no idea will exist since I'm injecting myself expecting positive results and not my soul being split in half, dear royal scientist I couldn't possibly know of because I'm currently the royal scientist and you don't exist yet..."