I’m writing this guide to explain how I went about to complete the Through Glass, Darkly quest in the Legendary quest line. It’s not meant to be the end-all, be-all guide, but just how I did it and what worked for me. I’m sure there are many ways that work, but this might give you some tips on how to complete it.
I will not discuss the lore of the quest, but if you don’t want to know what happens beforehand, you may not want to read this post, just in case.
You’ve collected your 25 eternal embers from Firelands bosses, bought your 3 sands of time and turned the quest in to Anachronos. He will then send you to Coldarra (which will be phased) where you will meet Tarecgosa. You will meet up with her in a special version of The Nexus.
This version of The Nexus you have to do alone, so no guild members or friends can help you out. Tarecgosa however will be with you for most of it.
Initially I went in without respeccing, but after a couple of tries I realised that my Felhunter kept dying, and so I respecced my Affliction spec to give me 2/2 Fel Synergy. While I was respeccing I also took 2/2 Demonic Aegis.
I also switched my Shadowbolt glyph for the Felhunter glyph.
I’d suggest bringing a health potion, something which I personally forgot. You definitely want to have a health stone ready, even if you have a potion.
As you enter The Nexus Tarecgosa is with you. The first mob she will make you invisible and you don’t have to worry about it.
After that you get to a room with a big sentinel and two dogs. Now, I was Demonology for this part, but I’m sure it works just as well as Affliction or Destruction. I killed the two dogs first, letting Tarecgosa tank the big sentinel. Just set my demon on them and dotted them up. Make sure to move out of the fire patches that the sentinel puts on the ground and you’ll be fine. Once the dogs were dead, it was an easy job killing the sentinel.
You’ll now start walking down the path towards where the first boss normally is. Watch out for the frost walls coming out of the sides, you have to pace yourself. It’s pretty much the same as the hallway in Icecrown Citadel if you remember it.
You’ll meet another couple of big dudes, but Tarecgosa will keep you safe. Then, however, she will run off and leave you alone to deal with 3 dogs. It’s no worries really, just set your demon on them and dot them all up. Use Drain Life to keep yourself alive if you need to.
Now there’s the hallway leading up to the landing before where Grand Magus Telestra can normally be found. This is a bit of a gauntlet event with lots of small adds who will keep re-spawning if you’re not quick enough.
I just powered my way through it with Hellfire and my Felguard using Felstorm. I’m sure as any other spec it can be done as well, just make sure you keep moving. Use Drain Life to stay alive if needed. I killed one set of adds (they sort of spawn in packs), then ran up to the next one.. killed it.. and so on.
When you get to the top, keep moving forward to Telestra’s room, or you might risk pulling the pack at the top when it respawns. In Telestra’s room you’ll see Tarecgosa frozen by two sentinels. They won’t aggro you though, so you have time to regain mana/health before you attack them.
I just burned them down one at a time (you seem to only aggro the one you attack, so you can take a break for mana/health in between if needed), while remembering to move out of the freezing ground ability.
After this Tarecgosa will run down the next hallway where a big wall of ice will be blocking the way. She will work on breaking it down while asking you to watch her back. A named, big dog will appear. He’s easy though – just keep your pet on him and dps him as usual while moving away from the shadowflame he will breathe towards you.
Once the ice wall is down you will see the old room with the ramps and platforms, only now there are only floating little platforms there. On each platform is a dragonkin. There’s a little disc in front of you which you will have to jump onto, and it will float you towards the closest dragonkin.
Your pet will bug out at this point and not join you, so you’re on your own. Make sure you’re at full health and mana before you jump onto the disc.
The dragonkin will cast shadowbolts, so use your Shadow Ward liberally. There are also floating orbs at the edge of his platform (a total of 4 I believe). Make sure you always use one before he does his big shadow damage move (you’ll see a warning that he’s powering it up).
Be careful no to cast anything after clicking the orb until you see a protective shield around yourself. I’ve heard that it can bug out/delay if you’re casting.
After the big add is down, jump onto his platform. Don’t jump any further yet because two small adds will appear and you’ll have to kill them. Once they’re dead, make sure you get health/mana back before jumping onto one of their discs to get to the next platform.
Rinse and repeat until you land safely on the other side of the chasm.
Don’t worry about the many adds here, Tarecgosa will appear and nuke them all for you. Quickly make sure you have your pet, get mana and health back, and run up the platform to where Anomalus usually is.
Now you will be facing the boss himself, a Twilight Dragon named Thyrinar. He does some abilities that you need to be aware of.
Ability 1: Twilight Blast
Use your Felhunter to silence it as much as possible. Shadow Ward on cooldown.
Ability 2: Twisting Twilight
A beam of shadow that follows you and puts shadowflame on the ground. Make sure you kite it around the edges of the room. Don’t get hit – you’ll die!
Ability 3: Twilight Restoration
This is a big self-heal buff and also makes him take 50% less damage. Make sure you use your Felhunter to Devour it!
He will also summon adds that do a Fire Nova ability. Try never to be close to the adds. Let the pet tank them, and fear them if they get too close to you.
Put your pet on Passive, because if he attacks the boss he will bug out (due to the boss flying). Make sure your pet is always in range to dispel the healing buff, and silence as many twilight blasts as possible.
When the boss summons an add (it will come running up the ramp), set your pet on it. Put an instant dot or two on it. I didn’t always do this, and the pet seemed to kill it anyway. However, I did notice that without 2/2 Fel Synergy the pet died (probably because I used Soul Link).
Just keep all your DoTs on the boss, use Drain Life as your filler (you’ll need it!) instead of Shadowbolt. The Felhunter glyph will help with health as well any time you dispel the self-heal.
You will spend most of the fight putting up DoTs, using Drain Life and silencing and purging the boss. Remember to put your pet on the add and kite the beam around the edges (make sure your pet doesn’t stand in it though!). Don’t forget to use Shadow Ward every cooldown as well, since he casts the Twilight Blast almost constantly, and your pet’s silence can’t get nearly as many as we’d like.
It took me a few tries to get him down, but it wasn’t nearly as hard as I had expected. The changes to Fel Synergy and the Felhunter glyph made a huge difference!
To help with the silencing and purging (and you’ll want this done as reliably as possible), I set the boss as my Focus target and keybound the following two macros.
#showtooltip Devour Magic
/cast [@focus] Devour Magic
#showtooltip Spell Lock
/cast [@focus] Spell Lock
Good luck with your quest!