It was unlocked in "Vilius Returns", when Vilius sealed the Knights' ability to turn into Titan Mode. He then took the five Dragon Cubes out of the Tenkai Knights and Dromus, deactivating Phoenix Mode, then combined the cubes and revived the dragon, but because he used his powers to create the dragon without a Dragon Key, the Tenkai Dragon was rendered unstable. The dragon would change from its good and dark forms. The dragon was so unstable that a single strike from Dromus was enough to split the dragon up into ten black and white dragon cubes, representing its good and evil forms.
The five white Dragon Cubes went into the four Knights and Dromus, while the five black cubes went into Vilius. Since the Knights had no Titan Mode, they were forced to retreat, which made them angry and left a big gap in their power. They now had to figure out how to defeat the Corrupted without Titan Mode in their arsenal. After a quick talk with his dad, Guren realizes that they need to change along with their powers if they want to stand a fighting chance. After attempting to beat Titan Granox and failing, the Knights work together to immobilize him. Their changing of strategy combined with the power of the Tenkai Dragon Cubes allowed them to access a new mode, Elemental Mode.
This change appears to be permanent, as now when the Knights travel to Quarton, they automatically appear in Elemental Mode. Their names have also slightly changed, to whatever their elemental attack is. It is deactivated by expelling the dragon cubes from their bodies.
Elemental Mode gives the Knights new colors, each of their respective element. Their helmets expand as well, and their wings get added onto, each slightly differently. Their legs, arms, and chest plate appear a different color than the rest of their body, and their weapons appear a slightly different color as well. Guren's Core Brick also changed color to red. This mode consists of black and white dragon cubes, not colorful cubes as within Phoenix Mode.
Elemental Mode grants the user powers which cause more damage then when in regular form. Their Tenkai Energy also increases, as well as their attack and defense. They are granted immense power that they did not have in their regular form. It is hinted that they also get new minor attacks, such as new ice arrows or flaming swords. It also grants each Knight a new power, their own elemental powers, as determined by their name. Each of their attacks are slightly different. The new elemental powers have proven to be powerful enough to turn enemies from Titan Mode back to regular mode in a single blow. They are also able to transform the BlasTank and Volt Jet into the Ice Walker and Flame Phoenix.
Bravenwolf Tenkai Firestorm
Bravenwolf's Elemental Mode is called Bravenwolf Tenkai Firestorm , Korean: 아바닝 브레이브, Abaning Beureibeu). His elemental attack, Tenkai Firestorm (Japanese: バーニングメテオシュート, Bāningu Meteo Shūto, Eng. Translated: Burning Meteor Shoot), allows him to summon a giant ball of fire on the tip of his sword and throw it at the target.
When he transformed into this form, his helmet slightly expanded on the top and at the edges, and his wings unfolded until it seems as if their are three pairs combined. His colors also changed from red and white to red and orange, all the white spots on his body changing to orange. His sword also glows orange and his Core Brick changed to red.
Tributon Tenkai Iceblast
Tributon's Elemental Mode is called Tributon Tenkai Iceblast . His elemental attack, Tenkai Iceblast (Japanese: ブリザードストライクアロー, Burizādo Sutoraiku Arō, Eng. Translated: Blizzard Strike Arrow), allows him to charge up his crossbow, then releasing a pure ice blast, freezing both the target land beneath before exploding.
When he transformed into this form, his helmet slightly expanded on the edges, and his wings unfolded until it seems as if their are two pairs turned on their sides. His color also changed from blue to blue and light blue, his tips of his helmet, arms, legs, and inner chest plate changing to light blue. His Tenkai arrows changed to a lighter shade of blue as well.
Valorn Tenkai Terrablast
Valorn's Elemental Mode is called Valorn Tenkai Terrablast . His elemental attack, Tenkai Terrablast (Japanese: ガイアエナジークラッシュ, Gaia Enajī Kurasshu, Eng. Translated: Gaia Energy Crash), allows him to generate a miniature earthquake by slamming his spear into the ground, causing many rocks to be launched at the target.
When he transformed into this form, his helmet slightly expanded on the edges and top, and his wings unfolded so that there are two strips sticking out over his shoulders. His color also changed from green to green and silver, his tips and top of his helmet, arms, legs, and inner chest plate changing to silver. His Tenkai staff changed to a lighter shade of green as well.
Lydendor Tenkai Lightningstrike
Lydendor's Elemental Mode is called Lydendor Tenkai Lightningstrike . His elemental attack, Tenkai Lightningstrike (Japanese: サンダーボルトブレイク, Sandā Boruto Bureiku, Eng. Translated: Thunder Bolt Break), allows him to shoot electricity from his body to the sky, causing lightning bolts to zap the targets.
When he transformed into this form, his helmet greatly expanded on the front, and his wings unfolded until it seems as if their are two pairs turned on their sides. His color also changed from yellow to yellow and light orange, his arms, legs, inner chest plate, and back of his helmet changed to light orange. His chainsaber and shield blade changed to a lighter shade of yellow as well.
His lightning strike can also make a gimungus lightning ball to go in and zoom around.
Dromus Tenkai Whirlwind
Dromus' Elemental Mode is called Translated: Gale Black Knight, Korean: 질풍 흑기사, Jilpung Heukgisa). His elemental attack, Tenkai Whirlwind (Japanese: 疾風竜巻県, Shippu tatsumaki ken, Eng. Translated: Gale Tornado Sword), allows him to summon a giant tornado on the tip of his sword after spinning 360 degrees and throw it at the target.
His transformation is similar to that of Bravenwolf albeit different colors. His helmet slightly expanded on the top and at the edges, and his wings unfolded until it seems as if there are three pairs combined. His colors stay the same: black and gray. The only difference is the gray color on his torso changes to a cerulean color. His sword and wings also glow cerulean. His eyes and the eyes and scar on his chest changed from red to blue.
Vilius Tenkai Dark TempestVilius' Elemental Mode is called Vilius Tenkai Dark Tempest (Japanese: ネオ・ヴィリウス, Neo Viriusu, Eng. Translated: Neo Vilius, Korean: 네오 비리우스, Neo Biriuseu). His elemental attack, Tenkai Darkstorm (Japanese: ネオダークエネルギーレイン, Neo Dāku Enerugī Rein, Eng. Translated: Neo Dark Energy Rain), allows him to summon 6 to 12 spheres of dark Tenkai Energy and release them at his opponent. Vilius also possesses the power to upgrade his own monsters into new versions of themselves. He can even able infuse dark energy to the Guardians by using four of the five Black Dragon Cubes.
His Elemental form bears a similar resemblance to his original form before his death, with several alterations. The upper chest armor piece is yellow, his horns are longer and yellow, his wings have expanded into four and the red areas are yellow, and his helmet has a new crown piece with yellow eyes. The prongs on his trident are a dark magenta color.