Twilight Caster

I heard that the Twilight Cultist Robes were going to be untransmogable (is that a word??)  so I was trying to look for something that shared the same colours and could pass for a member of the Twilight's Hammer.

Robe of the Thousand Needles
Hallowed Pauldrons
Corp'rethar Ceremonial Crown
Barbaric Cloth Gloves
Silent Slippers of Meditation
Malefic Girdle
Grieving Spellblade
Handbook of Obscure Remedies

Darkcaster Two - The Sequel

 Be careful when wearing this, you may be mistaken for a member of the Twilight's Hammer cult and painfully slaughtered by questing heroes.

I love how sinister this looks, however there is bad news for anyone who is Alliance and not a Warlock, you will be unable to get the horns. There is a Horde quest in Nagrand for the head, the warlock level 50 quests or the Felheart Horns that drop from Molten Core.
 
Stormspire Vest
Leggings of the Icy Heart
Ironweave Mantle
Netherweave Gloves
Mag'hari Ritualist's Horns
Stone-Worn Footwraps
Shroud of the Highborne
Cauterized Cord
Charmed Cierge

Darkcaster

I came across a mob in Mount Hyjal while questing that I though looked pretty cool. Unfortunately it is using the tier 5 Warlock head, so other casters will have to find another head, Wrath has some similar models, but none that are an exact copy that I could find.

Robe of Hateful Echoes
Boots of Shifting Nightmare
Hood of the Corruptor
Gloves of the Blood Prince
Living Mojo Belt
Mantle of the Tribunal