A while ago I have started to make the Monado from Xenoblade Chronicles. It is still a work in progress yet it still functions well.
The base stats if the Monado are the same as a netherite axe but with the sweeping edge of a sword. After using it for a bit the Monado will "activate" allowing you to use one of eight arts. They all work (except for purge and cyclone which still need tinkering.) After you select its arts you'll get the original mmonado back and repeat.
Things that I will need to improve on (suggestions are welcome):
-polish monado purge/cyclone
-make it obtainable in survival
-update it to 1.19.X
-probably more I can't remember
Here are what all the arts do if you were wondering
Buster-next attack does double damage
Enchant-strength effect
Shield-gets regeneration and absorption
Speed-get speed 4
Purge-next hit deals true damage
Eater-next hit deals extra damage as well as poison
Cyclone-next hit makes the victim unable to move for some time
Armor - Damage taken is halfed