He is an archangel with control over fire, earth, and metal. His counterpart, Atmos, has control over air, water, and plasmatic materials (like lightning).
Seaderus is said in Distance to have a sister named Katherine (nicknamed Kat), and they searched for Seadrus for their time rejoined together.
In The Runner Verse
He's protective of his friends, such as Atmos, and doesn't like being told what to do. He seems very distrustful towards Mister Oculus, and outwardly expresses his opinion in his blog.