[Crossover] A Complete Guide to Every Supporting Character

I've lost my memory, and, in the most cliched twist, I've been bound to a System.

Uh, the System is called The Supporting Character's Guide to Self-Cultivation?

...The fake ending has dropped.

Anyway, this is a story about a supporting character who tries to steal the spotlight, because otherwise she'll die.

P.S. The System has almost no presence, so don't expect it to be much help.

Theme: Fate can be reversed.