Lucifer presents himself as a calm, composed, and intimidating person overprotective of his brothers, and despite his harsh treatment of them, is shown to display a great love for them.
Levi is Dark and Moody, full-time otaku and shut-in.
Satan still got a rebellious and a bit of childish side to him and can be quite condesending smartass at times.
Beelzebub, being the Avatar of Gluttony, is always hungry.
Belphegor sometimes has a brisk temper, but he's also proactive, efficient, sensible,