Nightmare's End is a 2-player PvE Scenario map that can be played on Standard, Advanced and Expert difficulty. It is part of the campaign The Twilight Taint.
The Shard's magic is too aggressive, you need to unlock the full power of the four elements to be able to destroy it.
"The nightmares streaming from the shard had been stopped, but the Forge fragment remained a danger to all. It could not be returned, so had to be destroyed. But such an act would not be easy." — The Aedai Chronicles
Moon knew she would not be able to repeat Brannoc’s deed and weave a spell powerful enough to damage the shard. But this was the Shattered Land, it had seen the worst of the war of the elements , and had been torn asunder by magical power struggles for centuries. The land’s magic would be their only hope to overcome the strange power of the Forge.
The Amii had already made use of the land’s might, tapping into the strongest worldmagic nodes with their structures. This raw power should be strong enough to destroy the shard. If not, Moon decided, whatever created the Forge was not of this world.
Nightmare's End - Conclusion
"The pure force of the four powers was enough to destroy the shard. From this day, the Skylords saw the Forge with new eyes. It ceased to be just their home, a construct of great wonder, shades of darkness now cloaked it too. For, should the Forge ever fall into the wrong hands, it could bring death to the world." — The Aedai Chronicles
The nightmares streaming from the shard had been stopped, but the Forge fragment remained a danger to all. It could not be returned, so had to be destroyed. But such an act would not be easy.