Monspeet

is a demon who is a member of the Ten Commandments, a group of elite warriors of the Demon Clan handpicked by the Demon King himself. He was sealed away along with the rest of the clan in the Coffin of Eternal Darkness until he was set free by Hendrickson.

Appearance
Monspiet is a man with dark purple hair and a small mustache. Unlike the other demons (besides Meliodas) his demon markings are on the right side of his face, consisting of three lines, the outer two curving outward. He wears a cloak which covers most of his body and underneath he is shirtless with his torso and arms being covered with dark matter. He is very muscular.

Personality
Monspiet is a gentleman of sorts for a demon and the only one who understands the meaning of Derierrie's "taking from the ass" words. He also hates rude and ill-mannered people.

3,000 years ago
Along with the rest of the Demon Clan, Monspiet was sealed away by the Goddess Clan after losing the Ancient War against the Four Races (Human, Fairy, Giant and Goddess Clans).

Current arc
After Hendrickson managed to remove the seal, Monspiet and the rest of his fellow Demon Clan members appeared before the terrified former Great Holy Knight and Fraudrin in Dreyfus' body with Zeldris uttered Meliodas' name as if he knew him. After being informed by Fraudrin of the current events in Britannia, Zeldris suggested that they should head for Edinburgh Hill for recuperation of their severely drained magical powers due to the seal they're trapped in, which everyone agreed and left Zhuhur Valley by flight, leaving a terrified Hendrickson. Arriving at Edinburgh Hill, Monspiet and his fellow Ten Commandments find a castle in ruins and concludes that it was Meliodas who caused the destruction of the castle as if there was a great battle fought there.

Resting in the remains of Edinburgh as they began recovering their magic power, Monspiet came to discuss about the recent reawakening of two Albions from the north and the south where he sees Galan heading to the latter direction. After Galan came back, the demons sense Diane heading toward Megadozer, where Galan head toward her location along with Monspiet who the both of them overpower Diane until Monspiet sense the Boar Hat coming towards them which Monspiet sent a Hellblaze towards them, but, until to him, Hawk Mama eat it. While fighting Diane, Matrona appeared and recuse her while escaping from the Ten Commandments. Suddenly, Meliodas appeared out of nowhere through Merlin's teleportation and casually greeted the Ten Commandments who were alarmed of his sudden presence except Galan who was determined to finish off where he started.

Melodias battled and defeated Galan in less than ten seconds before warning Zeldris that the Seven Deadly Sins will defeat the Ten Commandments with everything they've got. In response, Zeldris and Fraudrin attempted to attack Meliodas from both sides, but he was teleported back to Istar. Galan was angered and humiliated by his defeat at the hands of the "Accursed Demon". Afterword, Zeldris suggest the Ten Commandments to split up and move across the land to regain their magic faster which Monspiet team up with Derrierie and the two head towards Bellford.

Abilities and Equipment
Like all members of the Demon Clan, Monspiet possessed a Black Mark similar to Meliodas, utilizing the mysterious jet-black matter as shown forming wings for flight and as a member of the Ten Commandments, he may be exceptionally powerful. His aura is so powerful that made the normally calm Hendrickson sweat in fear of their mere presence.

Abilities

 * Monspiet raises his arm and creates a large, triangular flame with the likeness of a bird. Upon being fired, the flame flies towards its target at an incredible speed, incinerating anything caught in its path and leaving a trail of fire in its wake. The flame is locked on to its target, homing in on it until contact is made.

Relationships
Monspiet and Derrierie seem to have a very friendly relationship, almost like that of a couple, when resting and regaining their magical powers they are always side by side, with Derrierie resting her head on his leg when they have nothing to do.
 * Derrierie