How about a Exoblade?That thing is awesome , check it out on the latest update, it may be some reference to the Elemental Excalibur from the Avalon mod.
Since it has that freeze debuff that even the final boss cannot stand , but that is sometimes.
If you want to make it. Give a Hardmode anvil to the guide (Crafting station) , and a Terratomere .
Wait. I am a few days to late