soul stone, power, revenge, following their God, etc. I'm being vague since if I say more it'll be spoiler but I suggest you read the novel. It's a good read plus the twists are so awesome
Oh so its a spoiler- eh nvm I thought I forgot or missed smthn but thanks for not spoiling. U better than more than half novel/manga readers out there~
At this point of the manga - They killed Jeong-woo cuz He was the leader of Arthia. Arthia was relatively a small rookie clan, but despite that it became a very successful clan. The other major guilds (8 clans) joined forces in order to destroy Arthia. + Jeong-woo was considered as a strong AKA a threat.
In the future - spoilers - no comment from me now (If you want some spoilers just ask though).
Ayo I didn't knew he was the leader of artia. Now it makes sense yey
Ayo someone tell me what did they gain from killing MC's brother?