User blog comment:GrandMethuselah67/Mage: the Awakening tribute sheet: Oliver Skarsgard/@comment-4867780-20151018024029/@comment-26322734-20151025043733

Well, during the time of Atlantis, the mages crafted the Celestial Ladder (which may or may not have literally been a latter -- it's hard to tell) to ascend to the Supernal. Some humans took control of the power it had to offer and colonized it -- those humans are the Exarchs. This broke the Celestial Ladder and the connection between the Fallen and the Supernal, which created the Abyss. The Oracles are the humans in the Supernal who also ascended using the Celestial Ladder, except instead of taking control, they fought against the Exarchs and created the Watchtowers to allow humans to awaken despite the Abyss. There are a lot of interpretations the game offers to this, but the way I see it, the most likely is that the Oracles suffered a Pyrric Victory and their souls became Watchtowers, and the Exarchs are stuck in their thrones, more beings of concept and symbol than actual humans anymore.

Oh yeah, the Abyss is massive. Abyssal mages are also, to put it lightly, freaking crazy. Any mage can allow abyssal taint into their magic to make their spells stronger, but the process is addictive and insanity-inducing. The Scelesti take this to the logical conclusion, being so maddened that they don't even see the world in moral terms anymore, but in terms of "Order vs Chaos" (where they would be Chaos). Scelesti themselves aren't terribly powerful -- at least not any more or less than the average mage, depending on their level. The Scelestus you really have to worry about are the Aswadim. They're archmages (humans that have ascended to the Supernal), except instead of ascending to the supernal, their souls have been completely corrupted by the Abyss. They tend to be the "Gods" of a Scelestus cult.