Nebulatower's tumblr is gone thanks to tumblr's old and insane policy of nuking nsfw stuff, but this is all I could scrounge up from different websites. From a bit of cross-referencing, they might be the same user as Pokonuki, found here: https://www.pixiv.net/en/users/38472361 / twitter.com/Pokonuki

Not sure, though, so I won't push it.

The asriel art is mostly also in that one generic undertale gallery, but this also has an extra pic not found there. Generally had to snoop around furrybooru, the archived tumblr from archive.org, and rule34 to find all this. Let me know if I missed anything.

What happened to nebulatower?

Base +5, AWolf343 +6