I totally think we're gonna have to confirm Bruce's suspicions and give him a heavy dose of papa/dr. brenne fucked up stuff as a lab experiment + abuse confirmation. Like there are two tracks we could do: repeated punishment via solitary confinment + killing the orderlies + being hunted + killing several government officials + dr. brenner's death + maybe pursuing vengeance but then choosing mercy and walking away, choosing her friends over her pain.

then there's the self-sacrifice part with contact to the monster + sacrificing herself to kill the demogorgon + walking away from mike to protect him + fighting the mind flayer + learning the mind flayer is her fault + her death

but I feel like her mother + getting adopted by hopper are also so good....

(do you see why I have such extensive lists? I'm bad at narrowing things down)