According to the dictionary, a mythoclast is a destroyer or debunker of myths. The Vex themselves didn't name the gun, our conscious minds did. It's literally called the Vex Mythbuster. I think the Vex Mythoclast is a vital key to finding the last chest in the Vault of Glass. A previous thread I saw said that lights within the VoG link to paths. Some more common paths (the red lights) and paths less taken with chests (blue lights). In another thread, I saw that when you open the very first door with the 3 sync plates, if you're decked out in raid gear, a special chime will sound when it is completed. In the video, when the chime sounded, the guy aimed down the Mythoclast's sights at the spire's light... And they were blue. This leads me to speculate that the key is within our senses. Hearing (the chimes sounding), touching (preventing the Templar to teleport), and seeing (the difference between red and blue). I hope this small post piques your interest. I hope it fuels you just as much as it does me to find the secrets within this mysterious game. Happy hunting, Guardians.