I blame the amount of time I spend killing Kael’thas every week for Ashes of Al’ar (5 character pairs, no joy) and this Wowinsider post about minor warlock glyphs in MoP for this. Also, I was bored.
Constraints: male blood elf (duh) warlock (to be able to use Glyph of Verdant Spheres).
Primary issue: the gear Kael’thas is wearing is all unique and unavailable to player characters. The bastard. Won’t drop Ashes, is a pain in the neck to kill every week, won’t even cooperate with transmog. That’s just singularly unhelpful.
Still, don’t think I did too poorly, all considered.
Helm: Replica Magister’s Crown. Just about the only helm that looked even remotely like the pointy thing Kael’thas is wearing.
Shoulders: Flarecore Mantle was the closest thing I could find. Reasonably flat-shaped like the original’s, mostly matching in color. (The shoulders from the Magister’s set matched even better in shape – only issue is, they’re very pink. No go.)
Robe: Robes of Ghostly Hatred. You’re going to need to head to Sunwell Plateau, kill M’uru, get him to cough up the Robes of Faltered Light (which I want for my priest, and still haven’t seen, so if you get lucky before I do, I hate you in advance) and then trade them in plus a Sunmote.
Belt: Ruthless Gladiator’s Cord of Accuracy. The only unobtrusive belt in existence. WTB more belts like this in the future (for all armor classes.
Boots: Infernoweave Boots. Not the only boots with this model, but probably the easiest to get, since they will only cost you a handful of justice points.
Gloves: Gloves of the High Magus. These are, on the other hand, the only gloves with this model, and they’re the ones that matched best. If you’ve already done the quest that rewards them, just pick out any black or red glove model, as long as it doesn’t cover the sleeves.
Cloak: Red Riding Hood’s Cloak (or Ruby Drape of the Mysticant, or Vengeance Wrap). Plenty of red cloaks in the game, but this is the one that matched the overly elaborate one worn by Kael’thas best. You can only barely see it in the screenshot, but it’s there.
Full outfit on Wowhead. I left weapons out of the screenshot, since Kael’thas himself uses none, but here’s what I would recommend: Golden Staff of the Sin’dorei (staff); Crux of the Apocalypse or Fang of Kalecgos (dagger); Muramasa (sword); Book of Highborne Hymns or, on the creepier end, Heart of the Pit (off-hand); Wand of the Demonsoul (wand). All from Sunwell Plateau, because where the hell else do you expect to find weapons with a Blood Elf theme?
Dreams of Iso'rath 