For those among you that love hardcore content, but hate how raids work in World of Warcraft, there is some good news on the horizon. Starting on September 20th, the first time you complete a Mythic dungeon each week you will be rewarded with a Mythic Keystone for a randomly chosen dungeon. With this magical little doodad you'll be able to enter the long-advertised Mythic Keystone dungeons and fight against more powerful enemies, all with the intent of getting even more powerful loot.
Each time you complete a Mythic Keystone dungeon your Keystone will level up, attune itself to a different dungeon, and offer you a chance to chase after even scarier enemies for even greater rewards. The first four Keystone levels will be fairly simple, at least as far as mechanics are concerned, but after that you can expect to see the enemies gain new modifiers and effects - not unlike the Rares and Elites in the Diablo series. Here's a few examples of these Keystone modifiers:
• Raging—Non-boss enemies enrage at 30% health remaining, dealing 100% increased damage until defeated.
• Bolstering—When any non-boss enemy dies, its death cry empowers nearby allies, increasing their maximum health and damage by 20%.
• Skittish—Enemies pay far less attention to threat generated by tanks.
• Volcanic—While in combat, enemies periodically cause gouts of flame to erupt beneath the feet of distant players
As you can imagine, this is going to provide a significant increase in difficulty when compared to the standard (and fairly easy) Mythic dungeons. Top it all off, you'll also have a timer to compete with in Mythic Keystone dungeons, though its not as bad as it sounds. Its purpose is not to encourage speedruns and mass aoe/stun strategies like the Challenge modes of old, but rather to serve as a gouge for a how well you are currently doing.
Now while the extra challenge is all well and good, I'm sure many of you are wondering about what's truly important - the loot! While the creatures (and bosses) within the Mythic Keystone dungeons do not drop any loot themselves, you will be able to find a chest at the very end that will reward two players with some high tier gear. The base item level of these rewards will start at 845 for Mythic Level 2, and go all the way up to 865 for a Mythic Level 10. Naturally, all of this loot will have a chance to be either Warforged or Titanforged, allowing it to potentially become even stronger.
For those of you that share my sort of luck when it comes to looting, i.e. none at all, worry not as there is a safeguard in place as well. After completing any Mythic Keystone dungeon, a reward chest will appear in your Class Hall the following week. The chest will come with a guaranteed piece of gear that reflects the highest Mythic level you've completed during the prior week, up to an item level of 880 for a successful Mythic Level 10 clear. Best of all, it will also come with a new Mythic Keystone so you can jump right back in as soon as possible.
That's about it as far as Mythic Keystone dungeons are concerned. You can read a few more details over at the Blizzard website, but this should pretty much have you covered for when September 20th finally rolls around. Good luck with the dungeons, and all of the loot too!