Disclaimer: I don't own Kamen Rider (belongs to Toei and Ishinomori Shotaro) or Avatar: The Last Airbender(belongs to Michael DiMartino and Bryan Konietzo)! I only own my OC, Kamen Rider Kaen!

AN: Just an idea I had after watching Kamen Rider OOO's Tajadol form for the first time.

They say that the original benders of each element were the animals, each one teaching the humans how to bend. The air bison bended air, the badgermoles bended earth, the Spirits of Twi and La bended water, and the dragons bended fire. To anyone, it would seemed like common knowledge. But before the dragons could even spew a spark of fire from their throats, there was another that could bend the element of fire... the phoenix.

For thousands of years, many phoenixes could bend fire into what form they wish. The people were amazed by this and began worshiping them as gods. These people studied the style of the phoenix's bending and soon made way into what became the first Firebenders on Earth.

However, the phoenixes disappeared and so did their style of Firebending. Some say they were hunted, others say they fought amongst each other, ultimately destroying themselves. No one truly knows what happened to them. It would take hundreds of years until the dragons surfaced, taking the phoenixes' place as the Firebending masters.

But now, it is time. From the ashes, the phoenix shall rise again!

Fires roared throughout the courtyard of Fire Lord Zuko's palace as he dodged a flame blast from his mysterious assailant. 'Just how did this guy get in here?' he wondered as he dodged another blast.

A few hours ago, the young Fire Lord returned home after dealing with disputes of Fire Nation rebels attacking a nearby Earth Kingdom village on the border. He entered the throne room, expected to be greeted by wife, Fire Lady Mai, but instead, came face-to-face with this "person." 'Who is he?' rang throughout Zuko's head.

Zuko's attacker was nothing he had ever seen before. The person was humanoid but instead of human skin, this person had green scales over his body, covering him from head to toe and a long tail came out of its back end. Claw extended from the tip of his hands and feet, and he wore black pants on his legs, while gray gauntlets were on his forearms. The beings head was like a dragon's head with horns extending from head, red eyes, and sharp teeth in his snarling mouth.

The dragon being aimed his fist at Zuko and a blast of flames shot out of his fist towards the Fire Lord. Zuko rolled out of the way to avoid the fire blast before he fired his own fire blast at the dragon creature, but much to his surprise, the dragon creature blocked it by simply raising smacking it away. Zuko raised his foot to fire another blast at the dragon creature but he dodged it as he charged towards Zuko. The young Fire Lord tried to back away from the humanoid dragon, but his opponent was too fast as the dragon creature sent a flaming fist at Zuko's face. He ducked, but the dragon creature used his tail to strike the young Fire Lord's legs, sending Zuko's back crashing onto the ground.

Zuko was about to get up, but stopped at the sight of the dragon creature standing over him with a flaming fist. "Your life is over, Fire Lord," the draconian being snarled.

The Fire Lord thought it was over for him, but before anything could happen to Zuko, a blast of fire struck the dragon creature in his side, sending his crashing into a pillar. Zuko turned around to see the one responsible for saving his life was a figure standing in the shadows. Though he could not see his savior's form, the Fire Lord could tell he wore a red belt with a circular black buckle that had the symbol of the Fire Nation in the center. Zuko's eyes widen to see small flames leaving the figure's hand. 'Who is this person?' Zuko wondered.

The young Fire Lord received his answer when the figure stepped out of the shadows and into the light. The figure wore a black bodysuit underneath they scarlet red armor. The chest was covered by a black, circular plate with the symbol of the Fire Nation engraved, and there was black torso armor that fastened the chest plate. The red shoulder guards resembled phoenix wings, and there were golden metallic bands on his wrists to fasten his red gauntlets. The red boots had two golden, jagged spikes on each foot; one on the toes, another on extending from the heels. His helmet was shaped a like a phoenix with wings extending upward and the 'legs' going down, while the head was etched onto the forehead. In place of human eyes were red, compound lenses.

The dragon creature recovered from the attack as it stood up, glaring at the figure across from it. "Kaen!" he snarled with recognition.

The figure, now identified as Kaen, simply walked towards the dragon creature. The dragon creature let out a roar as he thrust his fist out to fire another blast only for Kaen to make it away. Zuko watched with interest as he saw Kaen quickly bring up his other hand fire a stream of fire that struck the dragon creature in the chest. As the dragon creature was sent sprawling back from the attack, Zuko's eyes widen as Kane swung both of his arms to his sides and a pair of wings made of fire sprout out of his back. "What kind of Firebending is this?" the young Fire Lord thought aloud.

Raising his arms his arms above his head, the energy wings removed themselves from Kaen's back and turned into fire arrows shaped like feathers, floating in the air around him. They all seemed to have stopped, waiting for me to give the command until Kaen thrust both his arms at the dragon creature. The feathers made of fire they shot themselves towards the dragon creature and caused even more damage as they struck him in his chest arms and legs. While the dragon creature was recovering from the attack, Kaen stretched out his right foot, which immediately became engulfed in flames.

Zuko's eyes widen even more as Kaen charged at the dragon creature before giving him a flying-side kick that struck the dragon creature right in the chest. When Kaen's flaming foot struck the dragon creature, he exploded into a blaze of smoke, causing the Fire Lord raise him arm to protect his face from the heat of the explosion. Lowering his arm, Zuko saw the smoke clear away to reveal Kaen. Zuko looked up at Kaen with shock on his face. "Who are you?" he questioned.

Kaen looked at the young Fire Lord, and smirked underneath the helmet he wore. "A friend," he replied.

With that, Kaen leaped into the air and Zuko watched in shock as his savior used fire bending to allow himself to propel himself into the air before blasting off into the sky. Kaen's form became smaller and smaller until he was nothing more than a small speck. 'Who was that guy?' the Fire Lord wondered.

He had the feeling he would be seeing more of Kaen later on in his life.

AN: And that Kamen Rider Kaen for you! Please leave a review if you have any comments or constructive criticism. Also, this idea is up for adoption. Thank you.

Raika out!