Botania basically does this already with Timeless Ivy. You can apply it to tools that can be repaired on an anvil and make them repair with mana like regular manasteel or terrasteel items. Try to craft a TiC tool with the Ivy and 3 pieces of repair material for that tool. If it doesn't work Vazkii could potentially make it work like that or add it as a modifier so it will consume a modifier slot to make it balanced with the other "repair" modifiers.
The modifier should be Timeless Ivy because only the Terra Shatterer has its own internal Mana Tablet and even then you need a mana source in your inventory (Mana Tablet, Ring of Mana or Mana Mirror) for it to get repaired because the internal mana storage is only used for the activated ability.