What do you do in Zelda phantom hourglass when you have the phantom sword?

Answer:
Once the Phantom Sword is in your possession, go to the Temple of the Ocean King, descend as far as you can, and face your final battle with Bellum.
First answer by Squirrel Man. Last edit by Squirrel Man. Contributor trust: 2064 [recommend contributor recommended]. Question popularity: 2 [recommend question].