Maso

Maso is a devil of a materialistic underworld that’s akin to a red light distract, including a casino and hotel (which acts more as a grand castle than hotel). He enjoys coercing others to do immoral activities, as well as striking deals for their souls. Maso has a large almost indestructible ego, and sometimes acts on impulse, so long as it brings him entertainment.

He and Sado used to be in love, but fell out after an incident involving the death of the head angel thanks to one of Maso's demons. Although he and Sado are not exactly on "speaking terms", Maso enjoys playing pranks and destroying the peace of Sado's world any way possible-- just to get on Sado's nerves.

Maso doesn't care about how the human inhabitants of his underworld view him, however he does care about how his demon cronies see him. Due to this, he placed a curse on all his demons, which forces them to love Maso unconditionally. None of them realize this curse (other than Othello, who figured it out since he's very close to Maso).