Very quiet guy who usually just does his own thing without wanting to socialize a lot. He's not very talkative, but when he speaks, he is usually brutally honest because he doesn't like to pretend and sugarcoat things or lie. He doesn't mean to be rude or anything, he can actually be pretty kind if he wants to, but it's just his personality and he prefers to let actions speak rather than words. Most people don't appreciate that though, so he is usually seen on his own and has barely any real friends.
Enemies to lovers, they end up in fights a lot of the time bc Taeyoon tends to be passive aggressive and let out some judge-y opinions and Luka ofc just has to be brutally honest and very much dislikes them. But while he at first only tolerated Taeyoon for Sylva's sake, he eventually also started to develop feelings for him, oops.
His beloved boyfriend and the peacemaker between him and Taeyoon (most of the time at least)
They seem to have a normal sibling bond and are pretty close, especially since both of them struggle with their social life, even if their problems are very different. They are also very supportive of each other.