Mending runes

By making an amethyst rune and combining it with a mending book, any item you pair it with mending on it repairs first before any other item. For instance puting it on your chest plate for all of the xp to repair that item. You use a rune by combining the item with the rune in an anvil and you can't upgrade/combine that item with other items until you take off the rune. The mending rune doesn't have to be the only rune however, you could possibly use the runes to add an extra enchantment on a piece of gear. Like unbreaking and any other enchantment but brings down the effectiveness to other enchantments in that piece of gear. This way there is actually some strategy to enchanting. Do you want more sharpness? Then your sword breaks faster. If you want to mine faster then you get less for fortune. That's pretty much it.