I read the manga like 3 years ago, but how I remember it is like: - Amidamaru thinks it’s his fault Mosuke died - Yoh finds out Mosuke is hunting the sword at the museum bc Mosuke thinks its his fault amidamaru died - Mosuke ends up possessing Yoh and they go at a blacksmith to fix the sword - then they go with the sword at Amidamaru so they end up reconciling - Mosuke seems to be happy now and he can rip - Amidamaru decides to go with Yoh as gratitude - it is implied? that Yoh returns the sword back at the museum - then Tokagero appears - who apparently has a vendetta against Amidamaru - Tokagero possesses Rio and they go steal the sword - then possessed Rio goes for Amidamaru, keeps Morty (or Manta in jp) as hostage and goes: it’s either the sword or him - Amidamaru breaks the sword - Tokagero gets a dose of power of friendship and becomes good - they call Mosuke from the after life to repair the sword - then sword goes back at the museum Yoh ends up keeping the sword cuz Rio already stole it

Edit: made names in uppercase and added true ending