Level 1
Vampiric Aura
Your Basic Attack heal you for 5% of the damage. Nearby allied Heroes' Basic Attacks heal them for 3% of the damage done and nearby friendly Minions attacks heals them for 1% of the damage done.
Shadow Mend (D)
(!) Quest: Collecting Regeneration Globes increases all healing you receive by 0.5%, up to 10%.
(!) Reward: After collecting 20 Regeneration Globes, teleporting to your Shadowy Visage target heals you for 50% of you missing Health over 5 seconds.
Leeching Locusts (Q)
Carrion Swarm heals you for 25% of the damage dealt to enemy Heroes.
Level 4
Level 7
Level 13
Shadow Barrier (D)
Teleporting to your Shadowy Visage target grants you a Shield for 10% of your maximum Health for 4 seconds.
Level 16
Level 20
Mass Hysteria (R)
Hysteria permanently affects enemy Minions and affects nearby enemy Heroes and captured Mercenaries for 3 seconds.
Deep Sleep (R)
Increases Sleep's duration to 6 seconds and reduces the chance for the effect to break to 15%.
Dreadlord's Presence (D)
Shadowy Visage affects all nearby friendly Minions when cast, but the Abilities copied deal 75% less damage.
Claws of Shadow
Your Basic Attacks deal additional moderate damage and cleave to nearby enemies, dealing 75% of your Basic Attack Damage.
Nevertheless, it's a good work, i really like it.
P.S. : For a Dreadlord, Mal'Ganis will be classier :p
As for why I chose Varimathras over other Dreadlords to be the face of this kit, I feel like the other notable Dreadlords like Mal'Ganis and Balnazzar attack their foes more directly while Varimathras sticks more to the shadows - he stayed hidden under Sylvanas's protection in the Undercity for years before setting his plan into motion, the Battle for Undercity. I do agree that Mal'Ganis, Balnazzar, or even Tichondrius are more recognizable by players than Varimathras and since Blizzard most likely will not add two Dreadlords in Heroes of the Storm one of those other Dreadlords would be a better pick as the face of this kit.
EDIT: I decided upon Tichondrius to be the face of this kit. According to lore, Tichondrius is the leader of the Burning Legion's Nathrezim, or Dreadlords. He is also one of the final bosses within the Nighthold raid in World of Warcraft: Legion. While Mal'Ganis may be the most notable of the Dreadlords, I feel Tichondrius is the right choice.