For Thrall - Pretty much all throughout "Siege Of The Warmind" on Earth, repeat desired area on mission without having to leave and you'll be done in no time. For Knight's - "Siege Of The Warmind", the end where Omnigul shows up and summons them, defeat all 3 waves and die by Ogre to repeat without having to quit mission. You'll have it about an hour or less! For Wizard's - Dreadnaught Patrol, know the room where the Oryx Raid spawn room is? Run to the left tunnel then to the right tunnel outta the room for a constant summoned Wizard and repeat. You'll have it in less then an hour. Your Welcome!!! :-)