Because he spend the shortest time being taken over by Imu.
Holy Knights and Elders do not age, except when they get possessed by Imu. Then they age rapidly.
A couple of seconds in and Gunko's hair grew as much as it would in many weeks or a few months. So Imu has to be economical with his potential vessels. Their whole life time can maybe used up in one fight. If there wasn't such a strong limitation placed on it, Imu would use it all the time.
Garling looks like he aged normally, but he was a Holy Knight already as a young man in God Valley. He must already have been made a "zomby". That he still looks like an old man know indicates that he functioned as Imu's host. Perhaps even in God Valley...
Same goes for the other elders. Ju Peter has most life left, so he will be taken over and give Luffy a good fight in a future arc (Moon).
Holy Knights and Elders do not age, except when they get possessed by Imu. Then they age rapidly.
A couple of seconds in and Gunko's hair grew as much as it would in many weeks or a few months. So Imu has to be economical with his potential vessels. Their whole life time can maybe used up in one fight. If there wasn't such a strong limitation placed on it, Imu would use it all the time.
Garling looks like he aged normally, but he was a Holy Knight already as a young man in God Valley. He must already have been made a "zomby". That he still looks like an old man know indicates that he functioned as Imu's host. Perhaps even in God Valley...
Same goes for the other elders. Ju Peter has most life left, so he will be taken over and give Luffy a good fight in a future arc (Moon).
