Armarouge is a bipedal, humanoid Pokémon. Its body is primarily black, with red colorations on its cylindrical legs and hands, the latter resembling oven mitts. Its head is also red, with yellow sharp "ears" protruding from either side. The top of its head is yellow and has a fire burning on top, resembling the plume on a knight's helmet. Its face is covered with a black mask with three holes at the center, and its eyes have red sclerae and wisps emanating from its yellow pupils. Armarouge's torso and shoulders are covered in a yellow suit of armor and levitating large yellow pauldrons, respectively. The suit of armor has red accents on it.
Armarouge's armor is said to have belonged to a distinguished warrior, and is the source of its psychic power. The armor allows Armarouge to control its inner fire energy and use attacks. Armarouge is loyal and believes in fighting fair, willing to fight head-on no matter how strong the foe is. It focuses on first using its sturdy armor for defense before using high firepower in order to take down opponents. When attacking, Armarouge moves its pauldrons to its hands and puts them together to form a cannon, which it uses to shoot projectiles.
Armarouge is the only known Pokémon capable of learning the move Armor Cannon.
- Armarouge's name was misspelled as "Armorouge" on the official Pokémon Scarlet and Violet website; specifically, in the section describing the move Armor Cannon. This error has been corrected as of September 13, 2022.
- Armarouge has the same base stat values as its counterpart Ceruledge, just assigned to different stats.
Armarouge may be based on a knight wearing a suit of armor and long-range artillery weapons such as cannons and howitzers, while its personality may be inspired by the code of chivalry. Its ability to put its pauldrons together on its arms to form a cannon may take from depictions of arm cannons in fictional media. It may also take some inspiration from jinn, humanoid fire spirits of Arabic mythology sometimes depicted in popular media launching fireballs at other beings.
Armarouge may be a combination of arma (Spanish and Portuguese for weapon), armadura (Spanish and Portuguese for armor), and rouge (French for red).
Gurenarma may be a combination of 紅蓮 guren (crimson) and arma or armadura.