( Kyou senshi na mob, mujikaku ni honpen wo hakaisuru )
A rough English translation would be: “The Fierce Warrior Mob Unknowingly Destroys the Main Story” However, I don’t have a specific article with that exact title in my current knowledge base. This sounds like a synopsis from a naro (Shōsetsuka ni Narō)-style story — a parody or subversion of isekai/fantasy tropes, where a background character (“mob”) is actually overpowered and derails the original plot without realizing it.
It looks like you’re referencing a Japanese light novel or web novel title: