- The plot is an alternate universe version of The Legend of Zelda: Link's Awakening. This is why Oshus and Bellum seem so similar to the Wind Fish and DethI respectively. It even explains the whole All Just a Dream ending.
- Bellum eats life force from all things around it, starting with the Ocean King. This would also explain why the Ghost Ship took Tetra away at the start, as a means of bringing food to its master. But when you think about Skyward Sword, it makes much more sense than expected. If a creature consumes life energy, what more delectable source exists than a goddess?
- At the end of the game, Tetra asks how long they've been gone for, and her crew says that it's only been "about 10 minutes". Why 10 minutes? That was same amount of time the Hourglass could protect Link from the Temple of the Ocean King's curse initially.
Fridge / The Legend of Zelda: Phantom Hourglass