Just how powerful is Sin, the Beast, and nightmare?

The gems are harvested from the Beast then cut and polished before use in either creating gemlings or equipment for incredible power. The gems are a creation of nightmare, the power that causes corruption which is also Sin's domain. These crystalline manifestations of nightmare have allowed the exiles to perform feats that no other mortal could accomplish, from killing gods to bringing low cosmic horrors and their twisted victims. Now the Siege of the Atlas expansion is coming, and the Maven's progenitor has almost certainly arrived to cause problems. A being that tests the limits of limitless power, according to the Envoy. No doubt an exile will be there, gem in hand, to send them back to the void from whence they came.

This has been on my mind for a good while now, but I have not written about it before. How powerful is nightmare? How powerful is Sin that he could create such a corrupting force which defeats gods both terrestrial and eldritch alike? When will it turn from you fearing those that lay beyond, to those that lay beyond fearing you and the power you possess?

Too.

Sin is basically an ultraspecialist in how to undo the evolution of a powerful living figure into a god. He's otherwise utterly useless - sitting around on a pier chain smoking while we're out getting our nads stomped into paste by ordinary rares hopped up on tormented spirits. He only shows up when there's a fellow god to stuff in a jar.