Bristle is definitely meant to make the narrative consider the dark forest more. What is the point of having an eternal hell where bad cats will only get worse?
Bristle grows up being visited by a much kinder Hawkfrost who hates everything he was before and has finally gotten away from his father's claws
She learns through Hawkfrost and many other kind Dark Forest cats, like Snowtuft who helps her in canon!the broken code and who would be a good friend of hers in "Shattered Laws" my TBC redux.
Bristlefrost is fundamentally the most progressive cat spiritually, something that was slowly built up to throughout the other arcs.
Shattered Laws is meant to be the start of real change to the fundamental culture and issues of warrior society
And someone with a very unique perspective is needed to start that change.
Shattered Laws is primarily about spiritual change.
In the aftermath of OotS nothing really changed, despite this grand spiritual war
And in my version of AVoS you'd feel that really really badly
So it ends up producing three young cats:
Bristlefrost - Child of the cat who used her connection to the Dark Forest to turn the tide of the Great Battle and the Dark Forest cat who changed despite being very far gone
Rootspring - I hit her with the woman beam for a very important reason. Now, instead of just seeing Ghosts, she has the other abilities that Sisters she-cats inherit. It's a secret tool that will help us later
Shadowsight - Fuck canon for completely retconning his strong Starclan connection and putting ashfur there. I hate the imposter storyline, so instead Shadowsight is a medicine cat with incredibly powerful visions and a strong Starclan connection. This, of course, is inherited from his mother Dovewing, who has an intense Starclan connection as well, being trained by them.
What's the threat of Shattered Laws? Starclan Civil War. That leaks into the clans ofc. Because it's hard to send many prophecy's or do duties when your ancestors are fighting.
Nobody believes that it's real until Bramblestar dies and doesn't come back
Starclan never revives him.
He sits in limbo for moons, Ivypool (or maybe Hollyleaf, depending on what I do with her), as deputy, running the clan.
Eventually, his soul can't take it anymore, and with the help of Rootspring, Bramblestar passes on to Starclan.
Ivy doesn't become Ivystar (or Holly doesn't become Hollystar) until the last book when everything is resolved.