Regu  

, レグ

Regu is an artificial robot who resembles a young boy. His true age, background, and name are unknown as he has no memory of his past life before meeting Riko in the First Layer of the Abyss. Riko named him after her former dog. Regus body is incredibly robust and resistant to physical harm, yet it's surprisingly lightweight for its size. His arms can stretch up to 40 meters long each, equipped with Incinerator relics - high-powered beam cannons capable of reducing almost anything into ashes. However, using the Incinerator depletes his body's energy completely and makes him unconscious for two hours and ten minutes afterward. As an artificial being, Regu may be immune to the Curse of the Abyss, earning him the nickname "Aubade" or "Treasure of the Deep." Despite being a formidable fighter, Regu is shy and unassertive, blushing easily and crying when distressed. Unlike Riko, he gets anxious in dangerous situations and relies on her judgment to navigate through them.