HERE'S TAU!! if you thought haunted was the horror au you are sorely mistaken THIS is the horror au! with a dash of silly of course
if you're curious i can share what i have for the au so far in the readmore. it's long i'm sorry i like talking about my stuff
it's basically shadow of ronin events only different: ronin's more of a treasure hunter (doesn't handle the obsidian glaive + kidnapping of zane + pixal, that's someone else at play) but he's still finding the elemental forges & primal fulcrum for chen both for shits and giggles and for the money required to even move tf out of stiix
by the end of game events, ronin gets trapped in the ethereal divide because he's too far out of range to call for r.e.x. so he's stuck there for months (albeit with his spouse, archer who pops up as a ghost looking for him at some point) until morro uses the armor to get archer and hours later, after morro's left, ronin suddenly pops up in the museum.
misako gets a message to stay home because there's a "tar monster" in the museum but she ignores that and, after calming down the giant dragon-adjacent thing with multiple eyes, finds out that it's ronin!
tau basically looks like the drawing usually and constantly drips a tar-like substance, but when he gets upset his form just destabilizes into various monster-esque forms (one being dragon-esque). a lot of how he functions also no longer makes sense! he can't talk anymore because his ability to do so is just mostly melted. he can make weird sounds though and still knows sign language (whatever ninjago sign language would look like) he's basically irradiated! also his insides may be melted!
also extra bonus: because he was careless with handling ancient artifacts (not actually making sure they weren't cursed, using elemental artifacts despite the fact he shouldn't), when he used the elemental forges they ALSO kinda fucked him up before the ethereal divide did! he's elementally charged but can't actually... use it like he did during the final fight.
he's mostly got a few weird things going on that could be attributed to the four elements. dragon-adjacent form does however have the ability to breathe elements albeit only doing it out of instinct.