The Apocrypha of Yzarc

The Apocrypha of Yzarc is an ancient planar artifact in the form of a heavy tome. Within the many pages tells, in great detail and simplicity (somehow at the same time), how to bring about the end of a plane of existence and all of its sub-planes along with it. It was brought to the plane of Azeroth by the Norrathian god Solusek Ro. However, after his defeat, the Apocrypha vanished somewhere on Azeroth. Now planeswalkers, both good and nefarious, search for this coveted item. Some would destroy it. Some would extort it to their own ends.

Coming to Azeroth
The Norrathian god of magic, Prince Solusek Ro, originally came to Azeroth to regain his godly powers. To accomplish this feat, he discovered the Apocrypha whilst drifting in the medium between planes, the Blind Eternities. He took the Apocrypha, kept it safe, and travelled to Azeroth. It is unknown where exactly Solusek found the Apocrypha, whether or not it was drifting in the Blind Eternities itself (which is quite doubtful, as physical forms are torn apart upon entry) or if he found it on another plane of existence. He kept it hidden and overly-well guarded during his stay on Azeroth. He read it daily, memorized it even. Solusek obsessed over it, spending week upon week reading and reading.

At the end of the Usurper's War, Solusek Ro was killed by the hand of Mithaniel Marr. Mithaniel Marr, too, was a god of Norrath, being the god of Truth, Justice, and Light. However, Mithaniel had to renounce his godly powers to slay Solusek Ro, and as such, could not return to his homeworld by godly means. When Solusek Ro's divine powers escaped from his body, his tower of Solteris crumbled, and the Apocrypha vanished to defend itself. The Apocrypha cannot planeswalk like a 'walker can, but it can teleport to a seemingly chosen area on the plane it currently resides in.

Powers
The Apocrypha has the ability to completely remove planes of existence, such as Azeroth, from the multiverse. To the knowledge of most planeswalkers, it has never been used. However, the current planeswalker epidemic on Azeroth could soon change that.