Can You Help Me Level Up as a Supporting Character in a Martial Arts Novel?

I was transmigrated into a martial arts webtoon where people die every episode, <The Young Masters of the Namgung Clan>. And of all things, I became an extra villain abandoned by the family and the first to die a dog's death. No way, I have to save up money and leave the family before the original story begins! With that resolve, I put my part-time skills honed in my previous life to work, and what do you know? The strongest martial arts brothers, the tragic crown prince, even the vengeful Demon Lord. I've become entangled with the martial arts power players with an average age of 9? If it goes according to the original story, it'll be a bad ending where everyone dies... Alright, now ...