This mod adds a sword hilt crafted from obsidian, which allows you to absorb water and fire to make a blade. The sword hilt must be charged up and the amount of charge corresponds to the amount of water/lava it'll attempt to absorb. By pointing the hilt at the liquid after charging (by holding right-click), it will become a complete sword with durability and power based on amount absorbed. Water swords are obviously in infinite supply, but you should be careful about absorbing lava as lava is not renewable.