|Power Level||Demon lord|
Alzrius is a demon lord.
Alzrius is the Lord of the Flowing Flame, and rules layer 601 of the Abyss, Conflagratum.
His physical form is actually a large pillar of flame, and when his armies go on a campaign, the leader of the armies carries a piece of Alzrius's body as a torch.
He had a magic item, the flame amulet of Alzrius, in Polyhedron #135 (written by Erik Mona). Also, while not explicitly stated to be his,one of the armors from the article "Armor of the Abyssal Lords" (Dragon #270) is likely his, as it has a flame theme, and the article says no one knows which lord that armor is attributed to.