so far i've only really gotten to do it once, but there is something very interesting about writing something like umbrax. so far it's only really come up explicitly in discord; and has been implied once or twice on threads over here on tumblr but-- this is gonna be rambly, somewhat the nature of something like umbrax, so forgive me if none of this makes sense.
umbrax is described in the comic as being pretty explicitly bad. there's only one indication that it isn't bad, which is when john had realized that "hidden emotions" could be taken as more than just the negative that overtake and consume--to put it simply.
in the context of the comic, it separates umbrax from the invisible light spectrum. which i guess makes sense in reference to something like the other lantern entities; where obviously they aren't literally those emotions. ...that being said...i do think umbrax is a little different but not in the way that it completely is all invisible light but it is...invisible light, and invisible light is umbrax. and i think apart of the assumption can be made because it is stated--even in canon--to be related to the source wall. off course i will make anything about the fourth world, but it in my rework of umbrax it is a conception produced by the fragment of the source wall; broken off.
by no means is umbrax exactly a new god, no, it's not. it is more like ... a reflection--or rather a cast of the source, of the source wall, of what makes a new god a concept. i like comparing umbrax to an actual shadow because it's the only way it makes sense in the way that it is supposed to be "invisible light." the entity itself is ultraviolet--the shadow is just...what people see. the cast is reflecting whatever the ultraviolet light is beaming onto to cause that cast to be made.
the comic itself shows umbrax as having very little characterization of its own, which i think makes sense!! i think it works better for it to not have a characterization beyond it being a cast. that doesn't mean i don't think it has a ... mind of it's own. its just not in a way that i can properly express. it's not a person, but it isn't not? umbrax acts however it does when it is casting. it is in a constant state of change, of forward momentum, of cyclical existence. this is not always negative, but most often it's cast is shown to be negative. why? well, that comes from the fact that umbrax does not understand life, it doesn't understand emotions--more importantly--and it doesn't understand that what it could be doing could hurt people. nor does it necessarily care because it doesn't have any reference on what caring is. it will reflect and change and constantly be a shifting canvas of something that is and thinks and feels...
this is part of the reason why taro works ... so well as a sort of shell, or container for umbrax. taro's lack of sentience, their lack of true feeling; all of it, it makes it so the only thing umbrax can cast upon, is an empty nothing. that being said, umbrax isn't ... blind? and it does know that it's trapped, in one way or another. and it does know that the thing it's trapped inside doesn't feel anything. taro is almost a peaceful container for a thing that has no perception for what 'peace' aside from that it is the opposite to what it experienced before it was sealed, before it was split up and placed into these attempts--then centered into one. it doesn't dislike it's current state, nor does it like it; it just, sleeps.
that is the state of umbrax a majority of the time, a majority of interactions umbrax is asleep. it is sealed in a state inside a thing that it, for the most part, cannot effect.
in the situation where it is able to effect taro, it is still stuck inside taro, it can't just get out--at least not right now--but it almost sort of acts like a possession; in a way. and the way it acts is almost more childish than how taro actually does act. it's expressive, it's full of feeling because it's taking and clawing at everything around it; drawing it all out and experiencing it all. it doesn't have a frame for reference on the possible negatives because why would it care to, why would it have any idea on how to care to. it's also a matter of thinking about umbrax in reference to it "being" ultraviolet light; just as uv light is umbrax--it's already around, it's already there. it's one thing the comic does a decent job with--showing that umbrax has always been there, it was just a matter of it "arriving" and being conscious enough to take hold.
honestly one of my biggest gripes with how this whole 'motivation' is written with umbrax is like ... why does it want "earth to join its ranks" when that counters the idea that it is already there? yes there's the whole separation of umbrax and ultraviolet light and the emotion that is actually there...but for me the motivation of an entity like umbrax doesn't really make sense for it to want to spread and conquer or whatever in that way. a way to make that sort of work, is the idea that it was just casting onto sinestro. sinestro lead the ultraviolet lanterns in that comic, it's clear that he is "in control" in one way or another. umbrax casting most prominently his motivations makes sense in the context of my own umbrax retcons to make a little more sense on why it was being executed the way it was.
it's also interesting writing out those scenarios where it does sort of 'take over' while it's awake or waking up because-- it doesn't need taro to be actually functioning or online to do so. in fact, umbrax being awake is actively detrimental to taro's function. every circuit loses its power, every single aspect of code stops running and their database turns off; yet they still move. this was actually one of the aspects that caused the other attempts to die--or more specifically caused 394, to die. 394 was virtually identical to taro aside from the fact that 394 had emotions, it had sentience. it was a vulnerability that made the stress of umbrax's influence too much to handle; which caused it one day, in combination with other factors, to cease its function.
its just. head in my hands. umbrax is like a child. its new, in the context of other fourth world related things, it is new even in the context of other cosmic related things, especially things like the lantern corps. it resembles things that we already know, but it really isn't any of it. but it's able to recognize and cast onto those things we do recognize to try and experience and express those things, those aspects. in doing so, it is detrimental to most people because the main thing someone feels when faced with something like umbrax, in any form, is negative emotions. something akin to how anti-life is often represented. hopelessness, desperation, fear, driven to anger and disregard.
its an interesting parallel to think about when taro and umbrax are similar, in a way. taro mimics, they parrot, they adapt to others to better suit being around different people. umbrax casts, it reflects, it causes others to change so that it can experience. in a way its the same but terribly opposite.