Fraudrin
Fraudrin is a demon who has been using Dreyfus' body as a vessel for the past 10 years. He is a secondary antagonist of the Kingdom Infiltration arc, having conspired to resurrect the Demon Clan with the help of Hendrickson. He is also a member of the Ten Commandments, elite warriors of the Demon Clan handpicked by the Demon King himself. (Source: Nanatsu no Taizai Wikia)