A totally unnecessary character. If the entire point of cheap arse Wuxia WNs is to toss angry nobles on the MC to show off his agency, these sort of characters are there to completely rob the MC of his agency.
Just so much about these sort of plotlines just screams: "I have no idea wtf to write about or how to shoelace my random ideas, so here's a character that forces the MC to go through my side-quests".
It'd have been 100 times better, if the MC just randomly found that tiger by pure luck. It'd be total BS, but it'd be much better than being cornered by some random asshole into doing his bidding.
Also, I seriously doubt that's the MC's brother. He popped in early on, when the MC made a recovery, and he commented on the painting, or his martial-arts. Something along those lines.
Either way, it's not the sort of thing the brother would be aware of, or how he'd react.