If I may; where does your "cinder is a branwen" theory come from? What lead you to that potential conclusion?
okay, so, some context: this is during the hiatus between V5 and V6. it's middle of the night, and i'm neck deep thinking about raven's "family. only coming around when they need something." because while that fits yang, it hardly fits qrow; that was raven seeking him out, not the other way around.
the sensible part of me was having a wonderful time connecting this to summer—i.e. summer found raven because she needed help with her mission—however, the gremlin in me that revels in chaos went welllll... cinder & co showed up days later, needing something from raven.
now. this is also during the time when i'm already thinking it's a bit suspicious that words such as "dead" and "killed" were avoided when talking about summer (directly or in-directly), so to nib this chaotic thought before it had a chance to bloom, i had to check if the word "need" comes up at any point during raven's talks with qrow, yang, and cinder & co.
unfortunately for me, it does. qrow says it: "i don't know where the spring maiden is, either, but if you do, i need you to tell me." yang says it, too: "i just need you to take me to her." and finally, cinder says it not just once, but twice: "and now, all we need is the key to the vault." // "we just... need... the relic.", while watts doesn't.
so with that little thing established, the gremlin was free to roam as it pleased, creating a perspective that made certain other things look a little bit different, such as:
the parallels between cinder and yang that were at their peak during V4 and V5, including their interactions with raven
raven knowing 'fall' isn't cinder's original last name but one she chose (something something last name denotes family connection and cinder chose hers, essentially hiding hers), as well as describing emerald and mercury as "two children you've tricked into following you", implying that she has been keeping an eye on cinder even before beacon.
the feathers in cinder's brooch are described as "iridescent feathers (dark green & black)" in her concept art, pretty much what you'd expect from feathers of corvids (especially ravens and crows)
this brooch also sticks around for all of cinder's main outfits, perhaps implying it's important in some way (e.g. ruby's brooch was more than just an emblem, it belonged to summer)
raven's portals and cinder's explosions (that she creates with her semblance) look extremely similar—if not exactly same—outside the change of color; and being real here if summer's semblance also emits rose petals like ruby's does but white, i might just lose it here lmao
this is more funny to me but like. you can't go "you sound just like your mother" and then have both raven and cinder say similar things, e.g. some variation of "it's nothing personal", or even just raven being smug and referring to qrow as "little brother" only for cinder to come in moments later, smugly referring to qrow as "little bird". what is a poor soul supposed to think at that moment when i'm already preoccupied with "they never said summer is dead -> summer is alive" 😭
cinder's backstory revealing that she started from an orphanage obviously didn't help this matter, either
anyway, having said all that, i honestly don't expect this to lead into... well. anything. like if it did i would be surprised myself and i would never theorize about anything ever again, it would just be downhill from there lmao
ngl tho, it's great fuel for AUs.