does anyone have a theory or reason on why tehir cant regenerate the damage that is done t...

remember, when they were kids, jin used a pretty dangerous technique (a blood technique) and it messed up tehir's body internally to the point, it left him in a vegetative state for majority of his life,

mind you, tehir is labeled as the “noblest” and yet jin managed to “take him down his high horse” because tehir looked down on many of them when they were kids, labeling them as “trash” as such, so its basically like karma for tehir