The three versions of Asriel

Accurate

Yep

don't forget God of hyperdeath asriel

Still technically just regular Asriel, just with a buff

Accurate.
Also an anagram for Serial Murderer

Yes I am, how did you know? (This is a joke)

I saw a chart fully analyzing Asriel Dreemurr's name on r/Undertale. Asgore Dreemurr is also "Sage Or Murderer" which makes sense. Ralsei without the "i" at the end is Ralse,

Which is a character front a scrapped game Toby's brother was making and stopped.

Ok cool