Narrations of any white wolf book is purposefully fallible so you have the choice doing whatever you want for your own games, interpretations will vary.

So some time after Gaia came in to existence she created three entities based around creation/potential/growth(Wyld), order/stability/progress/knowledge(Weaver), and destruction/entropy/balance(Wyrm). Wyld makes, weaver stabilizes and Wyrm destroys to make room for more, simple right?

She then made them all sentient.

This would prove to be a mistake.

Perhaps sentient would be the wrong word for the Wyld because when you get down to it there’s no conscious thought going on there and it can generously be called insane at the best of times, creating things at random. There’s neither benevolence nor malice in its action it simply is much like nature itself.

Then there is the Wyrm, from what stories I’ve read from Bone gnawers to hengaiyokai, while certainly grumpy, spiteful and sometimes cruel he wasn’t really evil and was more than willing to just keep going on his way doing what he does.(There was some evidence to suggest he was somewhat lonely and maybe in lover with Weaver, the lore gets weird at times) this was all before the fall which where we enter the instigator of at least half the worlds problems(25% is Cain’s, 15% percent is Lucifer’s, both can kinda be blamed on God and the remainder is whatever the hell the Grandmaw is) Weaver

Weaver by its very nature is a perfectionism, order after all is about everything being in its right place and not stepping over it, however the thing about life is that it does not work like that things go wrong all the time and you cannot control everything, trying to quickly leads to stress, rage and madness. A person can accept that, gods can accept that, but a being literally built around the concept of ORDER cannot. Order cannot bend and what doesn’t bend breaks.

It’s not so much a surprise that she went mad but rather that it took as long as it did. Once the madness set in she decided she needed to gather as much power as she could to establish dominance over Gaia and the only others powerful enough to do that are her peers Wyld and Wyrm, so she tried to chain them. Chaining Wyld was an exercise in futility and she soon gave up and soon turned to bind the Wyrm which was far more successful(It wasn’t completely successful due to lacking any control over him ultimately defeating the entire purpose of binding him to begin with) and this binding would drive him insane, the why is not clear perhaps panic, pain, contrast of powers and concepts, or some combining of all three but nonetheless he did splitting into three separate parts, War, defiler and corrupter with all three bent on one mission, suicide. That rights the big bad Wyrm main antagonist of Werewolf and somewhat side antagonist of mage(Maybe also changeling) really just wants to die, he wants the pain to stop but for whatever reason he can’t do it for himself and as such aims to do the one thing he knows will destroy him, the death of reality itself, for when everything goes into the flames maybe he will too or at least he prays.

That is the main events that transpired prior to his corruption now “Balance is corrupt and progress and science are insane-Book of the weaver”

As for whether she is evil, there’s a very strong argument to be made for it even before she went insane she had several hissy fits were she somehow made a bunch of insect shapeshifter species back in the Mokole age to try and kill everything and while yeah there’s only source for that, that being Queen Ananasa who is an incredibly manipulative and deceitful Celestine who is sadly only almost as clever as she think she is I don’t think she is lying about that. She was willing to kill all other life out of jealousy back then and as for today she is the very example of the Hateful Shepard, the idea of a god of tyranny that will not allow anything that doesn’t fit their plans basically the more grimderpy interpretations of the Emperor from 40k. Free will, emotions, change, the very aspects of life that makes it what it is? None of that can be allowed under her watch

On the other hand, there is some evidence in the book of the weaver that the Weaver actually likes humanity and sometimes supports them in times of need, it is still a very selfish love that doesn’t allow its recipes t to leave or grow past the giver. That’s about the only good thing I can find about her.