Lore
Atar will not allow a stronger being than him to exist, and will immediately challenge any enemy being gods or angels which is why he is considered relentless. He is neither a god nor demon lord, he is Tyrannical Atar.
Name Origin
Atar is the concept of "holy fire" in the Zoroastrian religion.
Acquisition
See Atar, Tyrannical Darklord.