Cielo /MCB

Metal Card — Nitro Express (메탈카드 — 니트로 익스프레스, Metal Kadeu — Niteulo Igseupeuleseu): a pair of machine guns. They are firmly fixed via joints on Cielo's forearms. Sky Jet Shot (스카이 제트 샷, Seukai Jeteu Syas): Cielo fires arrow-shaped energy bullets from the Nitro Express. These energy bullets are also capable of piercing concrete in seconds. Homing Magnum (호밍 매그넘, Homing Maegeuneom): Cielo's ultimate skill, it fires energy bullets with homing missile properties. Unlike Sky Jet Shot, which fires continuously, it fires in small bursts to avoid detection by the opponent. Missile Launcher: Cielo can reconfigure both of its arms into missile launchers to fire energy beams.

Cielo is often impulsive and dives into situations based on his intuition. He makes a conscious effort to get along with people, but getting along with anyone can be a struggle for him, depending on who it is. While he sometimes warms up slowly, once he opens up, he clearly expresses his affection and sometimes teases those younger than him. He is incredibly loyal and always ready to use his strength and skill to protect his allies.

Cielo is a sky-blue Cardbot with an Air Force combat uniform motif, green eyes, white and orange coloring throughout its body, blue neon lights on its upper body, wings hidden on its shoulders, crossed markings on its chest, and green light variations on the sides of its head. Its head is designed as a pilot's helmet, resembling a hood worn over a cap. Its vehicle is a fighter jet based on the Yak-130 light combat aircraft.

After the Speranza crashed on Earth 4000 years ago, a symbol representing the crew's connection to Mukara was depicted on the right side of Cielo's cap's brim.

On the planet Machina, Cielo was a member of the Gigantrex team and one of three Cardbots he asked to join him on his spaceship Speranza's journey to found a new civilization. Cielo served as the ship's navigator. After the Speranza crashed on Earth due to Red Blitz's failed attempt to save Machina, Cielo and his teammates befriended the people of the village of Porcaca, especially Mukara, who, due to a lack of resources, sealed their Metal Breath, given to him by Gigantrex, and placed stone tablets concealing their Metal Cards in the Porcaca Ruins temple. At some point, all the stone tablets were stolen, and Cielo was put on display in the Mowtown Museum.