I propose the ability to upgrade katanas (custom textured diamond swords) to netherite swords. They would look the same, but they would have the stats of a netherite sword. The way it could be upgraded is via the smithing table, placing in an upgrade smithing template, the katana, and 2 netherite ingots (if it takes 2 ingots to make a neth sword, it is onlt fair that it should take 2 ingots to convert a katana to a neth katana)