A quick reference to all of the time travel we know of so far in Warlords of Draenor

  1. Garrosh goes back in time w/ Kairozdormu.
  2. He stops the orcs from drinking demon blood and forms the Iron Horde (or gets Grom to (probably this.))
  3. The Iron Horde has a massive military buildup thanks to the stuff Garrosh brings back and then builds the Dark Portal. 
  4. When the Dark Portal is opened, Kairozdormu, since he is a ~time dragon~ is able to dial our Azeroth ~35 years in the future.
  5. Since we don’t have Caller ID, we don’t let it go to voicemail and a bunch of Iron Horde orcs come out of the portal (our portal is crammed full of orcs, if you will.)
  6. The players have to go to Draenor stop the Iron Horde assult, and defeat all of the orc dads.