have you considered the upgrade system for these broken swords, i have litteraly grinded one dungeon for the last week and gotten one of the 2 swords to level 100 and it only gives a 20%increase in stats :D
this needs balancing for sure, some weapons are also horribly broken like the unsheat ability on the Isowakazi or what ever the katana is called. It wrecks everything in one single hit if you have enough stats in the leg stat does not matter if there 17 times your height and level.