I struggled with what to title this post. This isn't exactly a fan theory, since it has actual evidence and screenshots from the show. But take a look at the photo above, near the top right corner. This is from the episode Ocean Gem, when the ocean is drained. Now, that sword is HUGE - possibly even too big for the temple fusion statue to lift were it sentient. So, is the 5 gem fusion it portrays actually even BIGGER?
BUT, this is also not the first time the sword has been seen. Oh no, leave it up to Rebecca Sugar to always be planning something right under our noses. This wasn't something that the Crewniverse thought of while writing the Ocean Gem episode, no. This sword also appeared in Bubbles Buddies.
It's right there, sitting in the ocean! Steven and Connie pass it. And while exactly WHAT the object was may have been unclear in Bubble Buddies, Ocean Gem clearly shows that it is indeed a huge ass sword. Oddly, unlike fusion like Garnet, Opal, or Sardonyx, the weapon of the temple fusion (which I am assuming this is), is apparently not made of light like most other fusion and gem weapons. Pearl has been shown to use a real sword (and seems to own a lot of real swords), as well as the spears she pulls from her gem. Now, her spears poof when she looses concentration or drops them or at various times, but the sword she uses to train with is definitely a real object, much like the mysterious sword under the ocean.
How cool is it that there are little artifacts sprinkled throughout the show, left as tiny pieces of the huge puzzle that was the Crystal Gems past? This show is pretty impressive with all of its marvelous details! Be sure to check out the source for more photos and details!
Source
Twitter: Emerald