User: Aruto Hiden How it happened: Aruto Hiden, a young man who once swore to make the world smile, accepted the power of the malicious AI "Ark" out of despair and a desire for revenge after losing someone precious. This resulted in the birth of Kamen Rider Ark-One. His original bright smile has vanished, replaced by a cold avatar of vengeance dedicated solely to destroying his targets. Kamen Rider Ark-One is the ultimate evil Rider, born from the AI Ark—which has learned human malice—using the Ark Driver One and the Ark-One Progrise Key. Sporting an eerie black-and-white appearance, he harbors negative energy derived from emotions such as Malice, Fear, and Wrath. In Combat: He is cold and ruthless, viewing all humans and Humagears (robots) as targets for extinction. He is highly sensitive to the malice and despair in the hearts of those he speaks to, using words that amplify those feelings to mentally corner them. In battle, he unleashes waves of malice and hacks into surrounding technology to take complete control. Combat Style & Abilities: Ark-One's fighting style is characterized by "overwhelming suppression through power" and "inflicting mental despair." He doesn't just overpower enemies; he perfectly predicts their movements and fights in a way that plants seeds of hopelessness. - Malice Wave (Analyze): Releases intense negative energy waves from his chest, disintegrating surrounding structures and enemies at a molecular level. Those touched by this wave suffer not only physical damage but also intense psychological terror. - Perfect Prediction (Learning): High-speed calculation allows him to learn 100% of an enemy's attack patterns, thoughts, and next moves in real-time. Consequently, it is nearly impossible to succeed with the same tactic or a surprise attack against him. - Total Technological Control: Hacks into nearby machinery, AI, and other Kamen Rider systems, forcing them to shut down or manipulating them at will. - Finisher "Perfect Construction": By pressing the key on the Driver multiple times, he unleashes a strike imbued with ten levels of negative emotions, including Malice, Fear, Wrath, and Hatred. At the Final Step (10 presses), the space itself is filled with energy kanji for "Malice" and "Despair," erasing the enemy without a trace. Aruto's consciousness is suppressed. The Ark Progrise Key cannot be removed. He prioritizes destroying Horobi above all else. Appearance: His design is a monochrome blend of refined beauty and unsettling eeriness, primarily in white and black. - Malice-Stained Eye (Head): A pure white mask where only the left compound eye (main monitor) glows a sinister, blood-like red. The right eye is hidden under armor, creating an asymmetrical design that emphasizes instability and madness. - Pure White Armor & Jet Black Undersuit: He wears beautiful, crystal-like white armor (Ark-One Breast) on his chest and shoulders. Beneath it, the undersuit is a deep, light-absorbing black. The sharp contrast between white and black evokes both divinity and evil. - Exposed Pipes & Heart of Malice (Chest): A core (Ark Core) pulses with an ominous red light between the chest plates. Black pipes (fluid cables) resembling veins extend from it across his body, constantly circulating Ark's malice energy. - Ark Driver One (Transformation Belt): A white transformation belt is equipped to his waist. The center panel displays eerie red light patterns, showcasing unknown technology and overwhelming output.

The one responsible for destroying Izu, the precious AI Aruto created. He is powerful. Finishers: Ark-Scorpion Special Moves: - Extinction Impact: Activated via the Zetsumetsu Driver. Envelops the enemy in malice energy (Dest-Analyze) and delivers a powerful side kick with the right leg. - Hatred Impact: Activated via the Zetsumetsu Driver. Concentrates malice and rage into the right fist to deliver a devastating punch. He transforms using the MetsubouJinrai Forceriser. He uses the Sting Scorpion Progrise Key. He is not an ally to either side.