You gain a level 4 follower. They are not restricted on their modifications. Alternatively, you can choose to advance a level 3 follower you already have to level 4 and then gain a new level 3 follower.
You gain a level 4 follower. They are not restricted on their modifications. Alternatively, you can choose to advance a level 3 follower you already have to level 4 and then gain a new level 3 follower.