I think the reason he became healthy after waking up from his coma is bec of the part of twin’s soul inside him now, it gave him the few features and health.
At first I didn’t like this twist but when I thought about it didn’t change arrie in any other way so that’s great !
It is further explained in ch66 that Yoen's soul protected arrie from disappearing. In short Yoen's soul got destroyed instead of Arrie. Only Arrie's soul survived.
I think the reason he became healthy after waking up from his coma is bec of the part of twin’s soul inside him now, it gave him the few features and health.
At first I didn’t like this twist but when I thought about it didn’t change arrie in any other way so that’s great !