Opening the Dark Portal In this wing of the Caverns of Time , a group of players must defend the last Guardian , in a swamp known as The Black Morass . The Guardian Medivh , possessed by , attempts to open the Dark Portal to Draenor , while wave upon wave of dragonkin of the infinite dragonflight attempt to defeat Medivh in order to alter time and halt the invasion of Azeroth from Draenor . This time sequence is set about a few months before Warcraft I events ( circa 30 years before WoW ) . Entry . Completion of Escape from Durnholde Keep and the following quests . Dungeon denizens . Trash . Before the event : During the event : Loot . See Opening the Dark Portal loot . Walkthrough . The Black Morass begins with the five players entering the portal in the Caverns of Time . Once inside , it is recommended that the players all pick up a from before leaving the cave . The instance setting is a swamp which is filled with non - elite beast mobs that must be cleared . A path can be cleared straight south towards , but it is recommended to clear all trash in the areas where combat will occur during the event . Generally , only the islands and strips of land immediately across from Medivh need to be cleared , though a wider radius is safer until the group has a good sense of where the action will take place . The mobs can be easily rounded up several at a time by one player on horseback , led back to the rest of the party , and then burned down with AoE attacks . Once any player enters the area approximately 10 meters from Medivh , the event will occur . If Medivh dies , the encounter will reset itself in 5 minutes and players will be able to pick up a new Chrono - beacon from Sa ' at . The non - elite beasts will not respawn . The Opening of the Dark Portal . The event begins with calling for assistance and a portal quickly opening in one of the four designated zones : the first of 18 total waves of infinite dragonkin . Once a given portal has been shut or enough time has passed , a consecutive portal will be opened in a different zone and the entire encounter is timed from the opening of the first portal . At waves 6 , 12 , and 18 , there is a boss encounter . All of the portals will spawn mobs that will seek to drain Medivh ' s shield and eventually kill him . Waves 1 through 5 . Each of the first five waves of the event consists of one elite — either a melee - class or caster - class — that is tethered to the portal , and a stream of non - elite mobs . While the portal is open , adds will spawn every 15 or 20 seconds according to this repeating cycle : 1 Assassin , 3 Whelps , 1 Chronomancer . These adds will head directly towards Medivh , and must be dealt with or they will drain his shield and kill him . The non - elites all do small amounts of damage , and can be easily killed by any class ; AoE is not required , though abilities like Frost Nova and Snare can be useful for managing multiple adds at once . It is recommended , however , that one player focus specifically on the spawning creatures , while all other party members focus on the tethered elite . Frost - specced mages can do quite well at this job ; a combination of hunter and mage is also effective . The hunter ' s pet can be used as a tank for the adds while the mage burns each one down ; this also generally allows for good positioning near the healer . However , you should be smart about who you choose to put on the adds . The characters in the party with the highest dps should focus on the bosses , while a lower dps character ( preferably also one with higher armor or a pet ) should be assigned to the adds . The longer the boss stays up , the more adds will be spawned in total , leading to greater mana drained from the healer . If your mage has the highest dps , it is not wise to assign him or her as the primary add - killer , regardless of their ability to AoE . If tanking is done by a paladin , they can stand on top of the portal and easily aggro the non - elite mobs using AoE Consecration . If done properly , they won ' t even come close to Medivh . If you do not have a Paladin ( who can deal continuous DPS to all the adds using Consecration and Holy Shield / Retribution Aura ) , it is generally recommended that the tank holding the elite * * not * * attempt to aggro any of the adds , as they will almost immediately go after your healer . It may be possible to hold them like this if DPS is high , but it is generally simpler to let them through and have one or two ranged DPS focus - fire them down while everyone else stays on the tethered elite . Once you destroy the elite in a wave , everyone should kill the remaining non - elites and rest up for the next portal . The key here is pacing : while the next portal will open immediately after you down the elite ( or sooner , if you ' re slow ) , it ' s best to have healers and mana - based DPS classes drink up before they start in on the next rift lord / keeper . The longer you wait , the more adds you will have to deal with and the farther behind you will get on new portals opening , but if clearing the adds is going well , but you need not rush immediately from one portal to another if your group isn ' t quite ready . Each portal ' s elite will proximity aggro , but the adds will not ( they walk straight towards Medivh until they are attacked ) . The DPS assigned to adds can take advantage of this by opening with a spell with a long casting time , e . g . Pyroblast or Aimed Shot . Wave 6 : . Health : 89 , 000 Mana : 33 , 090 Special Abilities This fight can easily be done by four players , while the fifth defeats the spawning non - elite mobs . Alternatively , you can all dps him down and then use a beacon to clean up the remaining adds . takes the place of the or that would normally spawn with portal six . Chrono Lord Deja is an easy fight . The only ability of note is the Arcane Discharge . This is easily healed through , and the party member assigned to deal with the trash headed for Medivh should still be able to do so during this encounter . After Chrono Lord Deja is defeated , your group should have thirty seconds to a minute of rest before the seventh wave arrives , depending on how fast you killed him . Heroic : Pulls people towards him , making his chain attacks much harder to avoid . Additionally , his Arcane Discharge is much more frequent and damaging . It now deals around 4000 damage . Waves 7 through 11 . Same as waves 1 through 5 . Adds spawn according to this repeating cycle : 1 Executioner , 1 Chronomancer , 3 Whelps , 1 Assassin . Wave 12 : . Health : 110 , 000 Mana : N / A Special Abilities You have several options for dealing with his Mortal Wound debuff : The Mortal Wounds ability is applied every 3 seconds instead of 6 if Temporus is under the Haste effect . Therefore , this ability must be spellstolen or removed immediately . Temporus is one boss where it is highly recommended to allow the non - elite mobs to pass by , then when Temporus is defeated to drop a near Medivh to clean up the remaining mobs . You may need to use beacons at some point just to deal with the amount of adds who have aggroed to the party and are attacking casters . Just be sure not to use the beacon too close to Temporus himself , as it will fail and be wasted . The " Haste " buff increases run speed dramatically . Therefore , if your party has a mage spellstealing the Haste buff , then your mage should be the one assigned to drop a Chrono - beacon on Medivh about halfway through the fight . With the Haste buff , the mage can run to Medivh , drop off the beacon and be back to Temporus all within only 2 global spell cool - downs . If the group has no mage , a priest can use Dispel Magic on Temporus , a warlock can summon his Felhunter and use Devour Magic or a shaman can use Purge to remove his Haste buff . As of Patch 2 . 3 , Hunters can use a highrank Arcane Shot to dispel the buff Rather than trying to evade and kite Temporus , a protection - specced warrior can tank and spank him . His " Mortal Wound " ability can be blocked and is on a ~ 6 second cooldown , so timely use of Shield Block can allow it to fall off . Protection paladins should easily be able to keep up 100 % block through the whole fight if the Haste debuff is dispelled . This fight can get tough if your tank has trouble blocking or dodging Mortal Wound . In this case , a Subtlety rogue can evasion tank Temporus for the first 30 seconds by using Preparation . After that , the tank can step in . If a feral druid is tanking and Mortal Wound has stacked too high , a priest may want to keep a shield up ; the druid should still be able to keep rage . On a side note , Frenzied Regeneration is unaffected by the debuff , so it can be used to make a last stand , if necessary . Be warned that the threat reduction effect of Temporus ' knock back ability can make it difficult for the main tank to maintain his top position on the aggro list . It is recommended — in spite of the urgency of this fight — to grant the tank some time to build up aggro before the damage dealers join in . It ' s advisable to have the party kill two or three waves of the non - elites before starting to dish out damage on the boss . Heroic : Has a 6 second duration spell reflect . Wave 18 : . Health : 150 , 000 Mana : N / A Special Abilities The final boss and wave of the encounter , spawns alone . He will immediately head towards and attack him . If Medivh ' s shield is in respectable condition , it is recommended that the party rest up before the battle . While Sand Breath is arcane damage , it appears that arcane resist gear does not dampen the damage dealt when he uses the skill . In any case , it is not so much a problem as it might look , as long as the tank faces him away from the rest of the party . That way the healer can focus on the tank . Besides his abilities , Aeonus hits for very high amounts on any players . This is compounded by the Time Stop ability , causing Aeonus to continue to attack the highest aggro target while healing is unavailable . If healing is kept at a maximum , Aeonus will quickly fall to focused dps . Spell Reflection ( and bubble , of course ) can be used to negate the effect of Time Stop , and give the tank time to use cooldowns such as potions or Shield Wall if need be . Heroic bosses and repeat attempts . As in any other Heroic , players are saved to the instance and are given badges for the boss - kills ( Deja , Temporus , and Aeonus ) . This instance is unique in that you can fail after defeating either of the first two bosses and be forced to begin again . In order to prevent players from farming in this way , the game gives regenerated bosses new names and denies all loot from them . If Chrono Lord Deja is defeated , he will be replaced by the " on the next attempt . Temporus becomes the . Graveyard zerging Aeonus on Normal . It is possible to graveyard zerg . Should a party wipe on the last boss , run back to the instance as fast as you can . If ' s shield was around 100 % when you began the Aeonus fight , it should be at about 30 % when you rez . Drink and eat up then engage Aeonus again . The fight will not reset until Medivh is dead . Why should the Alliance help ? Some have questioned why the Alliance should help in opening the Dark Portal . After all , it was the opening of the Dark Portal that triggered the First War and the collapse of the kingdom of Azeroth . If the Dark Portal had never opened , the worlds of Azeroth and Draenor would have never been bridged . The orc s would have never arrived , and the wars never taken place . of the infinite dragonflight claims that " many lives could be saved " and " the resulting wars could be erased " . However , if the Dark Portal was never opened , it is explained by the Keepers of Time that the Alliance would have never formed . Instead , the races that form the Alliance would have descended into a chaotic civil war . Azeroth would have then been mercilessly crushed by the invasion of the Burning Legion . The Burning Legion would have then initiated an act of mass genocide , effectively destroying all life on Azeroth . This would have resulted in many more deaths than the First War and many others combined . Therefore , preserving time and opening the Dark Portal can be seen as " the lesser of two evils " . Why should the Horde help ? The Horde , having already succumbed to the demonic bloodlust on Draenor , would almost certainly have perished if they had never traveled to Azeroth . Draenor ' s wildlife had begun to die and the soil was turning to dust . Infighting was rampant , and had abandoned the orcs after the destruction of Shattrath City . Azeroth was salvation for the orc clans . As mentioned above , had the orcs not traveled to Azeroth they would not have been present to join the final Alliance against the Burning Legion . While the events of the second invasion would certainly have been very different without the orcs , it ' s likely the legion would have pressed through via another method . The native mortal races of Azeroth would then have been woefully unprepared to face the Legion . Notes . The events in the instance do not coincide with previous accounts of the opening of the Dark Portal . In other accounts , ' s involvement in the actual opening was only hinted at or not mentioned at all . These sources state that the portal was discovered by the warlocks of the Shadow Council and through their work , slowly opened . Even after the opening , it ' s told that it is only large enough to fit a single orc through . There was also only a single scout sent through initially . Medivh is not heard from for weeks prior to the opening , and does not return until well after the First War is under way . This contrasts with the instance ' s depiction of Medivh actively channeling and calling out to Gul ' dan as he does so , followed by an instantaneous opening of the full - sized portal , complete with stone arches , through which he greets a legion of orc warriors .