Seven Deadly Sins

The Seven Deadly Sins are a class of Demons who rank directly beneath royalty in Hell's hierarchy.

Trivia

 * They are implied to be based on real-life demons called The Seven Princes of Hell as stated in . It is so far, unknown if they all rule over their own rings, since Lucifer (who is part of the classification representing the deadly sin of Pride), rules the ring of Pride, but also all of Hell. It is also unknown if all of them will even appear in both shows.
 * So far, no demons have been confirmed to be a part of this ranking. However, three demons based on the Seven Princes that have appeared in the series have the possibility of being part of this order: the aforementioned Lucifer, a demon named Mammon, who owns a theme park in the ring of Greed, matching his representation in the classification as the sin of Greed, and Asmodeus, the owner of a sexually-oriented dinner theater restaurant found in the Lust Ring.
 * There is also mention of Satan on a sign that says "Satan Bless" that can be seen being held by a homeless demon in the pilot episode of Helluva Boss; additionally, many characters have cursed by Satan's name in a few episodes. Satan's existence would represent his position as the Wrath sin from the classification of demons.
 * Beelzebub, who is represented as Gluttony, is mentioned in the lyrics for "House of Asmodeus" in "Ozzie's". The aforementioned songs' lyrics imply Beelzebub is female in the series, whereas real-life depictions of Beelzebub are typically male.