So looks like I finally caught up. After trying to catch up for around one and a half year now, I finally did it.
Always barely reading more pages than Hussie updates, and I just made it to the beginning of a fresh new Act!
Oh, I can't wait to get to know all the kids and have their quirks described in detail before we start our advent-
HOLY SHIT, did that kid just blow up with an explosion from a mailbomb!? And that's the end of the Act!?
MOTHERFUCKER. WHAT IS HAPPENING HERE!
Also I love her since she's the first character to make blatant spelling errors, without giving a fuck. Finally I don't feel that bad about myself anymore, for having to look up a big chunk of fancy words Rose uses.
But if it's not a completely new character, I think this is either the Handmaid or a really weird antithesis of the Sufferer.
What made me think of the handmaid is the chumhandle, which just reminds me a bit of a doctor, her use of U_U smilies similar to Aradia's smilies with 0_0. Also this character writes in a british way, maybe some kind of influence from Lord English (if he's indeed English)? But this could also be explained with an obsession for the letter U.
However, The character revealing she's a prospit dreamer, speaks against this.
What make me think of Sufferer is the colour of the font ( a grey slightly brighter than Karkat's) and that these conversations mimic those of Karkat, just with an EXTREMELY FRIENDLY tone all over it. The Sufferer was known to be friendly to almost unbearable levels until he completely flipped out at the end. The presumely female gender of UU doesn't go well with this theory though.
So maybe it is just a new character?