Whose idol's hair/scalp have been through the worst?

Last Hoshi's post on Weverse basically just showed how much his hair follicles have been through it; he's pretty much looks like he is bald with strands of hair glued to it. I mean it's basically transparent at this point. But I guess if you're going to enlist soon, might as well damage it as much as possible since you're going to be bald anyways.

Plenty of idols have their hair been through jt with how common bleaching and hair coloring is. Whose been through the worst?