Have Eric die before reaching the City. I recommend letting him fall down the hole in the Chapter "
The Ancient One". This can be done by helping Nick and then failing the QTEs.
Interact with the prologue character covered in goo while travelling through the City.
Doing so will force Rachel into the cocoon to stop her from turning if she tells Jason not to kill her.
Then make sure she is not rescued by killing Nick while he goes to plant the bombs and kill Salim and Jason by dying in the eclipse by failing QTEs or by other methods.
Credit to ThePugHybrid for their
guide.