@ApolloX1209
That wouldn't be logical.
He doesn't know what rank the MC is, but he know the he's way too strong.
His life was saved by the MC.
He was willing to sacrifice himself to defend the guy.
He clearly saw that the kills were in self-defence... or self-preservation at the very least.
I think he might be the weak-ish bro with a lot of connections that the MC needs.
Jin-Woo has to keep his talent hidden as long as possible, but he also needs money.
If he was to suddenly solo finish dungeons, reap the rewards and sell them back to the guild, he would be found out in 2 seconds flat.
Now he has somebody who is afraid, loyal and beholden to him to help.