“There’s three things a body needs to do in the abyss: Find a portal, activate it and get out.” – wise planar chant.

Things are simple in the Abyss. You take a scheme too far and you piss off the wrong demon lord, you know what it’s gonna be like. You will probably lose so much and end up serving him, or maybe if you are lucky you might get a chance to escape the Abyss and hide somewhere till the whole thing cools off. But capture a demon lord’s child from a prime (not just any demon lord but a major one at that) and the Abyss shows its true face. Especially when you’re not yet a trye lord of the Abyss, but struggling to become one.

An assault on the 452th layer that ends in its complete destruction, the death of the lord and the reformation of the entire plane to its new master’s liking. A massive onslaught that decimated nearly every resident of the plane, apart from those lucky enough to flee. A cambion and an alu-fiend find themselves in Plague-More, survivors of such an onslaught. Free of their masters and the oppression of the Abyss, they start a new life on the planes, leaving behind their old, miserable lives. Most of it, at least…

Planescape - Halfbloods