Level 1
Scourge of the Frozen North
Grants bonuses to Basic Abilities against Minions, Mercenaries, and Structures.
Archlich of the Scourge
Grants bonuses to Basic Abilities against Heroes.
Level 20
Wasteland (R)
Enemy Minions and captured Mercenaries slain within Death and Decay's area of effect increase its duration by 0.5 seconds each, up to a maximum of 4 seconds.
Slaves of Kel'Thuzad (R)
Chains of Kel'Thuzad affects up to three nearby enemy Heroes and its duration is increased to 4 seconds.
Necromancer Supreme
Gain both the bonuses of Scourge of the Frozen North and the bonuses of Archlich of the Scourge.
The Call of Kel'Thuzad (D)
Enemy Minions and Mercenaries slain by Necrotic Aura summon Ravenous Ghouls and enemy Heroes slain by Necrotic Aura summon Skeletal Knights to assist you in battle. Ravenous Ghouls prioritizing attacking enemy Structures and Minions and last for 6 seconds and Skeletal Knights prioritize attacking enemy Heroes and last for 10 seconds.
Mana:
Cooldown: 12 seconds
Afflict the target with a random disease that spreads to nearby enemy Units. Each disease lasts 4 seconds and can only affect each target once for each Outbreak.
Blood Plague
Reduces affected targets' maximum Health by 10% and reduces healing received by 25%.
Frost Fever
Reduces affected targets' Attack Speed and Movement Speed by 15%
Unholy Blight
Deals low damage to affected targets each second over the duration.
I like to say it again and again. Soo much randomness dont belongs into the nexus.
As for Outbreak, I thought a little bit of randomness would eventually make its way to the Nexus however I think I have something to replace it that keeps the same feel without the randomness you mention.