Lan Zhan's love interest and the one who was friends with everyone is indeed Wei Wuxian. But then he died and this boy named Mo Xuanyu summoned him, using his own body as a vessel for Wei Wuxian's soul. So yeah, Mo Xuanyu is dead and Wei Wuxian is using his body.
Also, people usually draw original Wei Wuxian and Wei Wuxian in Mo Xuanyu's body similarly for the sake of convenience, it's the same guy after all. It shouldn't be taken so literally, the rest of the characters are not able to recognize him, only us, the readers can do so. Think about it as a Clark Kent/Superman kinda thing, Superman is literally just Clark Kent without glasses, but inside of the movies/comics, the people are not able to recognize him. They just didn't make them look drastically different for the sake of our convenience.
Oooooh that's why they look alike lol It was supposed to make things easier for the readers but it just made everything even more confusing for me Σ( ￣□￣||) I tend to take things too seriously (⊙…⊙ ) my mistake but know I'm curious to know how Mo looks like since he didn't really get to do his own appearance ╮(￣▽￣)╭
I am a little confused lol before I keep reading the story there are some things I would like to understand. Mo XuanYu is dead and Wei Ying took his body? The one who was friends with everyone and Lan love interest is Wei? The names in the flashback made everything worse... I can't understand anything lol Why in the flashback Mo and Wei look the same?