Caverns of Time:
The Caverns of Time is a place in where you can find 3 different instances: Escape from Durnholde Keep, The Black Morass and the raid Hyjal Summit.
In this guide we’ll be focusing on the Opening the Dark Portal (Black Morass) part. Level requirement for this instance is 68.
There aren’t many quests in here.  Old Hillsbrad: The Black Morass is the follow-up from Old Hillsbrad Foothills, and should be gotten before venturing in here.
A good tank is recommended, but not needed. But do note that a tank with AoE capasities will make thisa bit faster and easier.
A good healer will be needed as one of the bosses will press your healer. A druid with HoTs is great, but any healer class can do it, as long as they are aware of the abilities of the enemies/bosses.
Last some good DPs is needed. This instance is a DPS race, and the longer it takes to clear a portal, the more adds will you have to deal with.
Map of the area:
This instance can be parted into 3 phases, just like Old Hillsbrad Foothills.
As you enter the instance, talk with the guy and get a Chrono-beacon, and drag it onto an Action Bar for future use. The Chrono-Beacon will, when used, summon a “Time Keeper” dragon, that’ll help with killing the mobs and it’s a VERY good tank (I’ve never seen it lose aggro). Turn in  The Black Morass and get  The Opening of the Dark Portal.
When you exit the grotto you start in, you’ll find yourself in a swamp, with a lot of non-elite beasts. Fight your way down towards the portal and make sure to clear all mobs around the portal spawn-points to make it easier.
This is where you should be going
Yup, it’s The Black Portal as we know it, only with a different look ^^
Anyways, MAKE SURE TO CLEAR ALL NEARBY MOBS BEFORE PROCEEDING
Phase 1: Wave 1 to 6:
When you’ve cleared all nearby mobs, have someone walk up to Medivh. When someone is close enough this’ll show up
at the top of your screen.
The % shows how much of a beating Medivh can take before you lose, and the “wave x/18” shows how many waves you’ve crushed so far.
Anyways. When one’s near to Medivh, a rift will spawn and a rift lord will show up together with it. The job is to kill the rift lord, and then move on to the next portal and so on. If you kill the rift lord too slow, then another rift will spawn, as they’re on a timer, and not waiting for your group to finish the already existing rift.
While the Rift is active, some non-elite adds will spawn and wander against Medivh. Having one of the DPS to kill those is a good idea, and any kind of DPs can take them alone. They will spawn in intervals of 15-20 seconds and in a cycle of this: 1 Assassin, 3 Whelps, 1 Chronomancer. Those adds will not aggro before somebody attacks them, which will give peoples time to use some long-casttime abilities.
When you’re killed the current Rift Lord, have the mana dependent classes drink, while the tank moves on to pick the next Rift up. The mana-users can then join when they’re ready.
Every 6th wave will consist of a boss, plus the normal amount of adds.
Wave 6 – Chrono Lord Deja:
Attacks and abilities:
- Time Lapse — Magic AoE debuff: Attack speed and movement speed reduced by 60%.(dispellable) Twenty yard range.
- Arcane Discharge — Arcane Damage: Hit all targets in a fifty yard range for 2200-2600 damage.
Chrono Lord Deja will spawn instead of a Rift Lord, but notice that the normal adds still spawns. Therefore you’ll still want one person to stay on adds and rest on the boss.
He’s a farily normal tank-and-spank fight, although Arcane Discharge can prove a problem. It is important that the healer heals everyone up after the 2nd Discharge.
When he’s dead loot him and rest up before the next wave begins.
Phase 2: Wave 7 to 12:
Wave 7-11 is nearly the same as wave 1-5, except that the cycle of adds is like this: 1 Executioner, 1 Chronomancer, 3 Whelps, 1 Assassin.
Wave 12 – Temporus:
Attacks and abilities:
- Mortal Wound — Debuff, cannot be dispelled: Decreases healing on target by 10%, stacks up to 7 (as of patch 2.2) times. Lasts 12 seconds.
- Haste — Buff, can be dispelled/spellstolen: Temporus’s attack speed and run speed is increased dramatically (+200%).
- Knock Away — Physical Damage, AoE: Knocks back all nearby enemies and reduces the threat of those affected.
- Untauntable — Temporus cannot be taunted.
This boss would be fairly easy if it wasn’t for him Mortal Wound Debuff. As it can stack 7 times, the tank will recieve 70% less healing that normal, which can prove fatal. There are more ways to avoid it though:
- Have all five members focus on defeating the boss quickly before the debuff stacks too high, then kill the remaining non-elites after he is dealt with. Warriors can use last stand and shield wall towards the end to try and stay alive: if an off-tank is available, losing the MT towards the end can be an acceptable loss since there will be time to res afterwards.
- Use an off-tank to switch aggro. Switching aggro can be quite difficult, however, because Temporus is not tauntable.
- Try to evade Temporus for long enough that the Mortal Wound debuff wears off. The debuff is applied every six seconds and lasts 12 seconds. Note: If the tank runs Temporus too far away from the portal, he flies back and resets himself to full health immediately, making a wipe almost inevitable.
- Apply a paladin Blessing of Protection, switching quickly to an off-tank that can busy Temporus while the debuff wears off.
- Use an ability or item which increases avoidance, such as dodge trinkets, shield block, etc. to avoid or block a Mortal Wound attack. Avoiding even a single one will cause the stack to expire before it is reapplied again.
The Hast buff is a magical buff, and a mage can therefore spellsteal it, whivh will make the mage a lot faster.
Anyways, as long as the tank manages to avoid the Mortal Wound debuff often enough, this fight should be straightforward; Kill the boss, while having someone killing the adds every now and when. But if someone overaggro the IT IS IMPORTANT that they stop attacking, as he cannot be taunted.
When he dies, loot, enjoy and rest up 😛
Phase 3: Wave 13 to 18:
These last waves will spawn faster that the other waves, which will stretch your group if you’re lacking DPS. This is also why most groups save their Chrono-Beacon for wave 13-17, as the dragon can boost your groups DPS by A LOT.
The adds will spawn in this cycle: 1 Executioner, 1 Vanquisher, 1 Chronomancer, 1 Assassin. (No easy (whelps) for you now ;))
Tackle the waves as you want to, and when you reach wave 18, Aeonus will make his entance.
Wave 18 – Aeonus:
Attacks and abilities:
- Time Stop – AoE Debuff: Stuns all players for four seconds.
- Sand Breath – Arcane Damage: Deals 3500-4500 damage with a cone in front of Aeonus.
- Frenzy – Buff: Increases Aeonus’s attack speed. Can be countered with a hunter’s tranq shot.
Now the fight begins looking like fun. As soon as Aeonus enters, he’ll run straight for Medivh. Let him beat Medivh until the whole group is ready and then engange him. Make sure the Medivhs shield can take some hits, or the tank’ll have to engange him at once.
NOTE: No adds will spawn in this fight
As you might have noticed, Aeonus is a dragon. Therefore he also uses a breath attack. This means that the tank has to turn him away from the rest of the party, to avoid making the healer waste too much mana. This is a test for some healers, ‘couse of the Time Stop ability. That makes it important for the healer to keep the tank be topped off at all times. (Better be safe than sorry). Apart from that ability though, it’s just a normal fight.
Kill him, loot him and watch the small scene that shows up.
On your way out, make sure to turn in  The Opening of the Dark Portal and get Hero of the Brood.
You’ve completed the second of the CoT instances and hopefully had some fun in doing so 😉
I hope you enjoyed this guide ^^
If anything’s missing/wrong, tell me and I’ll fix it ASAP (wouldn’t surprise if something is wrong :P).
This time I managed to get a LOT of pics compared to my previous guide 😀
Please note that the group I was with was TOTALLY overgeared for the instance as we just went through normal to bet the Karazhan key, so if it somehow looked easy, don’t think it is 😛