Random relevant lore i forgot about until i was writing Young Phosphora's bio last night oiuyhgtfd
The proper process of a titan becoming part of the monster world as an island-host, specifically those dragged in by the stair shaper, removes their ability to vocalise and make noise by themself, causes a form of amnesia that completely erases any memories of a former life and home in another dimension, replaces any and all alternate methods of communication with a telepathic link that only allows them to communicate with other nearby island-hosts in addition to changing their head shape to be large and flat, almost like the surface of a miniaturized colossal, to act as their island. Of course, these changes aren't as scary as one might think- each titan learns exactly what's going to happen to them before they make the choice, and if they don't want to become an island-host? they won't be forced into it by any means.
The process has one major flaw, though- being that it was designed specifically for transporting and transfiguring titans from faraway lands and distant dimensions, completely built around exploiting the velocity a titan would need to reach the monster world from the other side of the beyond or build up by shifting through several other dimensions and realities until they clip into the monster world.
Of course, the problems this would cause were evident when the intended final titan, Phosphora, entered the monster world. As the prism dimension has been incredibly close to the monster world since the very beginning, the titan had barely any velocity- they didn't even require assistance from the stair shaper, an open prism gate was enough for Phosphora to just step through instead of hurtling through spacetime- And thus never lost their memory or nonverbal communication [or any form of communication at all, actually- the light titan already lacked the ability to create sound, so the prism dimension's silent language of flashing lights was the only one they knew]. All the other titans came from far enough away to have gone through the Process perfectly, so seeing this occurance provided valuable, yet no longer useful information- If a titan originating from a planet or dimension close enough to the monster world they'd be able to see, contact or visit it without needing to travel incredibly long distances, they'll experience less side-effects of the Process, possibly not being effected by it at all if they come from somewhere close enough.
All this to say- Neuros lacks 'proper' titan features (such as being permanently silent, or having a heavy-set body to balance out a massive head), not because they're defective by any means- Their sudden formation, directly within the monster world's own pocket dimension, left them completely unaffected by the process, which was assumed to just be because the process hadn't been prepared by the stair-shaper for a new titan- though even when it attempted to force them (or at least, what Neuros percieved as forcing) through the process a while later when it finally succeeded in transposing them to the nexus, Neuros ended up so terrified their first and only response to the situation was self-defence (IE; randomly lashing out on account of Being Terrified, Not Knowing What Was Going On, Not Existing A Week Ago and thus Not Knowing Who This Guy Is Or What It's Motivations Are And Immediately Assuming It Wanted To Hurt Them Because Everything Feels Scary When You're A Teenager And A Week Old At The Same Time), proving strong enough to completely shut it down (at least, they think- really it was just the process failing because they're from the monster world itself as they happened to be 'fighting' the stair shaper statue) and get outta there; thus, they remain as the only titan on the monster world to keep their true, unchanged titan body- Completely unaffected by any external forces, able to do whatever they want and keep whatever features they want, and perhaps most importantly to them, not being an island host. they do NOT want to be an island host and have decided that is the WORST thing for them to be.
(EDIT FOR CLARIFICATION: the stair shaper ain't do anything wrong, it and Neuros just had the worst misunderstanding in known history-
The stair shaper saw how happy the other titans were after deciding to take it's offer and become island hosts, despite having told them all the effects it would have on them beforehand. It kind of stewed with that thought for a while, came to the conclusion that becoming an island-host would make all titans happy, because it turned all the external titans it knew into island-hosts and they were happy, and the natural titans who were already island-hosts were happy too- so surely that's what made titans happy? hosting islands with lots of monsters to keep them company?
Unfortunately trying to turn Neuros into an island-host to make them happy, too, since they seemed so sad and alone for a good while after their formation, didn't... end so well. Especially since the stair-shaper straight up forgot to ask if they wanted it or actually tell them what was happening. Turns out not every titan wants to be an island-host, after all.
From the stair-shaper's perspective, it took in a sad and lonely child, tried to give them everything they needed to be happy in life as a gesture of goodwill, only for them to bite it on the arm several times and angrily run back outside and into the bushes like a feral cat.
From Neuros' point of view though, they got taken to somewhere strange and terrifying, then had a strange and terrifying stone wizard start doing strange and terrifying magic on it which changed their body in strange and terrifying ways to be something they didn't want to be, so they very reasonably fought back and ran away because it was too strange and terrifying for them to want to risk talking to it...
Also yes, Neuros is normal and not terrified of everything now. Mostly. They still avoid anything relating to the nexus unless the desire to See The Thing manages to outweigh every other instinct in their body, like if perhaps that thing is a seam-tear to the human world that somehow managed to open in the nexus. It gives them the chills.)
