Rudo

Rudo is a former Sphereite and Regto's adopted son whose false convictions led to him being sentenced to The Pit. After being saved from a group of trash beasts, he joins the Cleaners as part of a plan to enact murderous vengeance on his accusers. His vital instrument consists of 3R, a pair of gloves from the Watchman series, which were given to him by Regto before his death.

[Spoiler] His full name is Rudo Surebrec. [/Spoiler]

(Source: Gachiakuta Wiki)