The Seal is Broken is part of the main questline in WoW Mists of Pandaria Remix, but many fans are having trouble completing it.

This quest begins and ends with Lorewalker Cho, and you must seal 12 Sha Fissures and eradicate the Sha of Doubt. If you didn't know, the Sha of Doubt is that large shadowy creature that lives near you in the Jade Forest. Here's how to start and complete The Seal is Broken quest in WoW Remix Mists of Pandaria.

You can start the quest The Seal is Broken by talking to Lorewalker Cho in The Jade Forest at coordinates 44.6, 67.0 after completing the Last Piece of the Puzzle. After accepting the quest, talk to Mishi, Lorewalker's Cho Companion, who is standing next to him, and say "Let's do this, Mishi!" This will turn Mishi into a large serpentine dragon that you can ride, and it will begin circling the Sha of Doubt.

You need to seal 12 Sha Fissures by using your UI's skill (it should be bound to the 1 key) on black and white smoking circles around the Sha of Doubt. In total, you need to seal 12 Sha Fissures, and Mishi will keep circling the Sha of Doubt until you complete the quest. There's plenty of time to do it, and even if you don't get them all in one go, you can always go back.