Acronix

Acronix is one of the Time Twins and the younger sibling of Krux.

History
40 years prior to the events of Hands of Time, Acronix and his brother Krux were the original Elemental Masters of time. While Krux could go back in time and pause time, Acronix could go forward in time and slow down time. Although Acronix used these powers to great advantage, he was still a very skilled warrior without them.

After the Serpentine were defeated by the Elemental Alliance, Acronix and Krux, knowing that they were more powerful than the other Elemental Masters, decided to betray the alliance and use their powers to control all of Ninjago. The other Elemental Masters fought against Acronix and Krux, but the two proved too powerful. With the Time Blades forged by Ray and Maya, Wu and Garmadon fought a lengthy battle against the Time Twins at the Monastery of Spinjitzu. Eventually, Wu and Garmadon used the Time Blades to absorb Acronix and Krux's elemental powers, rendering them normal men.

Knowing that the power to control time was dangerous, Wu and Garmadon used the Time Blades to open a vortex that would leave the Time Blades lost forever. However, Acronix and Krux decided to go through the vortex themselves, which left the two "lost to time." Acronix would be lost in the time vortex for 40 years. However, unbeknownst to Acronix, Krux was somehow immediately teleported back to Ninjago and experienced a vision of the future foretelling of Acronix's return.

Dark Island Trilogy, Part 3
Falling asleep at home following his battle with Clouse, Wu would be stricken by a horrible nightmare filled with several visions of the past, such as the return of Acronix and Krux.

The Hands of Time
Forty years after the monastery battle, Acronix emerged from the time vortex at the ruins of the old monastery. There, he unexpectedly was confronted by Master Wu. Eventually, a battle between the two broke out. After nearly falling to his death, the Forward Time Blade lands in the center courtyard and causes time to skip a minute, ultimately saving him and allowing him to claim the weapon. With the blade, he succeeded in accelerating Wu's growth, making him feel older. When the Ninja interfered, he defeated them with ease and headed to the Ninjago History Museum to meet someone after being assumed dead. When he arrived to the museum, Dr. Saunders revealed his identity of being Krux as they hugged and began plotting their revenge.

Ninjago.com Description
Because Acronix was carried off inside the Time Vortex, the past 40 years have gone by for him in the blink of an eye. So while his brother Krux aged in real time over the four decades, Acronix looks just the same as when he disappeared. As an Elemental Master of Time, Acronix could manipulate time forward, both with great speed or in slow motion. Although Wu and Garmadon stripped him of those powers, he remained a tactical fighter who Wu described as one of the best he’s ever seen. Acronix’s skill with any weapon can lead him to be overconfident at times, and he will throw himself into a fight like a blunt object with little concern for the consequences… mostly because he’s sure there’s no way he could ever lose! Acronix loves all the technology and gadgetry he never experienced because he missed the last 40 years. His favorite is the BorgWatch.

Appearances

 * 70626 Dawn of Iron Doom

Season 7: The Hands of Time

 * 65. "The Hands of Time"
 * 66. "The Hatching"
 * 67. "A Time of Traitors"
 * 68. "Scavengers"
 * 69. "A Line in the Sand"

Dark Island Trilogy

 * Dark Island Trilogy, Part 3