I'm a Martial Arts Supporting Character, Can You Raise Me?

In my past life, I struggled through countless part-time jobs, only to suffer a head injury in an unexpected accident. But when I opened my eyes, instead of a hospital ceiling, I see a traditional Eastern-style house? That’s right! I’ve reincarnated into the novel "The Noble Sons of the Namgung Clan," the very book I was reading before I died! Of all places, I woke up in a crazy story where people drop like flies… And worse, I’m a villainous side character who gets abandoned by her family and is the first to die a meaningless death! Fine. With all the experience I gained from my past-life jobs, I’ll escape this house before I meet my doom. Wait, what? Every time I show off my skills, the main characters start falling for me? The cold-hearted older brothers, the vengeful cult leader, even the tragic crown prince—all of them are getting tangled up with me! If the story follows the original plot, everyone is doomed to a bad ending... Alright! If it’s come to this, I’ll save them all. A well-raised side character can save many lives!!