The hammer may not have had a mind, but it had a soul as a Legendary Hammer.. Same with the Ratatoskr Devil fruit, it didn't have a mind, it was a soul.. The Ratatoskr's Soul get consumed by the Hammer, not the other way around.. Like Chopper is not guided by a Human mind, he's the Deer that gained a Human mind.. When you see Chopper's innocence, cluelessness or being gullible about stuff that's his Animal side as a Deer, a Human didn't take over Chopper.. The '' Squirrel mind '' didn't take over the Hammer, the Special Hammer gained an Animal mind that deviates from a normal Squirrel or Mythical Squirrel.. Being mythical Squirrel, Ratatoskr's mind is still a basic Squirrel, just with Super powers..
When you see Ragnir bowing beside the treasure chest, that's not the Squirrel's behavior, that's the Hammer's personal trait, which is Ragnir..
It got heavier on its own so it can get lighter..
That's really not an issue.. If there's another worthy wielder for a time being, it doesn't have to imply loyalty switch.. It depends if Ragnir can do those distinctions or not..
When you see Ragnir bowing beside the treasure chest, that's not the Squirrel's behavior, that's the Hammer's personal trait, which is Ragnir..
It got heavier on its own so it can get lighter..
That's really not an issue.. If there's another worthy wielder for a time being, it doesn't have to imply loyalty switch.. It depends if Ragnir can do those distinctions or not..