
I don't know if this is right, but I think what he meant is "min woojin's identity". Since min woojin will become min siwoon when the heir die, it means that the identity, the person called "min woojin" will disappear forever, but the person "min siwoon" will still be alive. and about that last sentence, I don't really get it too lol

Im my opinion he meant by "im not going to die, but you are"that woojin (the blonde dude) will take his place as the "heir" so metaphoricaly he "dies" like his existence/life will end here as "Woojin" and he kind of becomes the that sick boy (idk the name xd).
And if i remember correctly he said that he did all of this to be with Taemin once more.
╮( ̄▽ ̄)╭ btw i really liked that metaphore...im a sucker for them.

Yeah he didn’t mind losing his name what he wants is to gain power to protect and to live with the one he loves
I might have missed something but what did the true heir meant when he said “I’m not going to die soon, you are”? Like why did he say min siwoon was gonna die? Was it metaphorical? Also what did min siwoon meant when he said “doesn’t matter, because in the end, it’s all for him”? I’m having a hard time understanding the ending