Character Description (From the Regretevator WIKI):

Mach is a blocky, light-skinned humanoid with dark brown hair tied in a low ponytail. She wears a curved purple top hat with a white ring, along with an open suit of the same purple color and a purple shirt. She also wears lighter purple pants and black shoes. Mach has a neutral facial expression along with red glowing pupils and always seems to have her hammer with her, which has a long brown handle, black grip, and bright red head. Mach also has the girl torso.

She / Her

Voice Description:

I imagine Mach's voice to be somewhat monotone, however still can be expression. Also somewhat robotic in nature.

https://regretevator.fandom.com/wiki/Mach

Lines are from Mach's canon dialogue in Regretevator