Shadow Disciple
The secretive Shadow Council subtly eliminated all rogue Warlocks to establish their position as the true and only practioners of the recent demonic magik's discovered by Gul'dan. The Shadow Disciple is a warlock at the height of these arts - surpassed only by Gul'dan himself - and is bound to bringing the will of the council to pass, whatever it may be. Using his talents in the darkest magic imaginable, the Shadow Disciples are capable of a great many ways of bringing suffering to the opposition.
Game description: Mystical Hero, adept at ranged assaults. Can learn X, X, X and X. |n|n|cffffcc00Attacks land and air units.|r
Names: Lugwash the Malevolent, Okten the Devourer, Mortug Hellcaller, Brekzar Soulblighter, Geruk the Brutal, Kush Tongueripper, Tarmek the Defiler, Venfarg Throatcutter, Kerdub the Bloody, Karag the Bringer of Sorrows, Torzon Bonesnapper, Ugash the Backstabber, Kor the Merciless
Old list:
Sorlan the Wise, Vortox the Cunning, Marvaron the Cruel, Xorrax the Malevolent, Zhandor Stormbrewer, Zul'tar Darksight, Raz'kan Doomcaller
Shadow Disciple:
6.1 - Electrocution
Same as Forked Lightning only the bolts are red (to show that Shadow Disciple's still use the nature's elements, but in a darker way).
Background: Twisting the ways of ancient shamanistic magick's, the Shadow Disciple focuses a lethal blast of electric energy over an area. This concentration is attracted to individual creatures and builds up to unleash a deadly strike of electricity upon.
In-game description: Calls forth a cone of lightning to strike the enemy.
Level 1 - 85 damage per unit.
Level 2 - 160 damage per unit.
Level 3 - 250 damage per unit.
Notes: I think you're taking the Palpatine similarity too far Rommel.
There must be a cooler name though... Doom Sparks? Black Charges? Electric evil?
6.2 - Eye of Kilrogg
Summons a floating eye to scout the area. Is equivalent to the Owl Scout.
Background:
In-game description: Summons an invincible scout unit which lasts 60 seconds and detects invisible units.
Level 1 - Summons light Eye for 100 mana.
Level 2 - Summons moderate Eye for 75 mana.
Level 3 - Summons best Eye for 50 mana.
Notes:
6.3 - Demonic Ritual
summons a Felhound (Or lesser demonic creature) to do the SD's bidding. Spirit wolf replacement;
Background:
In-game description:
Level 1 -
Level 2 -
Level 3 -
Note:
6.4 - Flesh Harvest
Summons a Reaper (Cookie's Burining Horror model) at the expense of a friendly unit's life. The Reaper is a powerful demon with a devastating attack and can revive nearby corpses as invulnerable zombies (similar to Avatar of Vengeance).
Background: This highly-sought after spell is rewarded only to the exceptionally dedicated followers of the Shadow Council. Dedicating his power to the very heart of his demonic lore, the Shadow Disciple sacrifices and uses the energy of a nearby minion to summon forth an immense creature that few know the true origin of. The awesome effigy of terror and destruction lives only to maim the enemies of the Disciple, with an immense power over the bodies of both living and dead.
In-game description: Targets a friendly unit to create a Reaper, a heavy land unit. Units killed by it turn into zombies.
(Formerly: Ultimate - Soul Harvest
Calls forth the spirits of the Twisting Nether (a la Locust Swarm). Enemies killed by them rise as skeletons.
Background:
In-game description: Calls forth dozens of spirits from the Twisting Nether, which proceed to rip apart the enemy. Any units killed are raised as skeleton warriors.)
You wrote Tainted Warlock instead of Shaman. Anyway, such guys are called Dark Shamans, though in my opinion they just cannot exist.