Supporting Character Upgrade Manual

He has SSS-level powers but can only act as a passerby? After being bound to the "Supporting Role System", I upgraded by acting as a backdrop for Destiny's Child, and went from "unknown supporting actor" to "Best Supporting Actor" - the more roles, the stronger I am, but I can never steal the limelight from the protagonist. Until one day, the protagonists all knelt down, and I was forced to pick up the script: "Everyone, is it my turn to read the lines?"