Krux and Acronix are the primary antagonists, known as the "Hands of Time," who seek to control all of time after their defeat 40 Years prior. Krux's role was to patiently wait in Ninjago as the Museum Curator "Dr. Sander Saunders," secretly breeding the Vermillion Snake Army from Great Devourer eggs and forcing Kai and Nya's parents to build armor for them. Acronix, the younger twin, suddenly returns from a Temporal Vortex, kicking off the Season by striking Master Wu with a "Time Punch" that causes him to age rapidly. The main goal of the Vermillion Army was to steal metal and kidnap builders, including Cyrus Borg, to construct the Iron Doom, a time-traveling mech that could use all Four Time Blades. A key highlight of the Season is the mystery surrounding Kai and Nya's parents, Ray and Maya, who were initially suspected of being traitors but were actually forced captives of the Time Twins. The Ninja, struggling without a fully operational Master Wu, repeatedly fight against the Time Twins and their Vermillion Commanders (Machia, Raggmunk, and Blunck) to prevent them from gathering all Four Time Blades. The conflict becomes personal when Kai and Nya use their Elemental Powers to form a Fusion Dragon to retrieve the Final Time Blade from the Boiling Sea, during which Acronix hits Ray with a Time Punch. At the end of Season 7, Kai and Nya follow the Time Twins back to the past to stop them from changing history; though they succeed and restore the timeline, Wu is left behind battling Krux and Acronix, and all three are lost in the Temporal Vortex.