Looking for Stories Told from a Supporting Character, Cannon Fodder, or Background Character's POV, Preferably with a Female Lead (Female-to-Male Transmigration Is Fine Too)

Looking for books similar to *Slay the Gods: I Transmigrated Into Shen Qingzhu’s Younger Sister, but I’m a Snake Demon*. Quick transmigration, fan fiction, anything goes. I don’t mind if the female lead and the protagonist are on opposing sides, as long as she feels like a real, fleshed-out person from her own perspective. Preferably no everyone-loves-her trope and not too much description of her looks. Thanks!