You've offered your service to a Lich in exchange for the secrets of true necromancy.
Level 3
Necromancer's Bidding.
Your shadow blast and minions are the conjured spirits of the risen dead and inflict the Soulbound condition. When a living creature with the Soulbound condition dies summon a shadow minion in their space. Your maximum shadow minions increases by 2.
Level 7
Power of the Grave.
You may cast Necrotic Spells without Pilfering Power by sacrificing shadow minions equal to the Tier of the spell being cast.
Level 11
Empower Undead.
Your shadow minions deal 2xKEY damage ignoring armor and Greater Shadows deal 3xKEY damage ignoring armor.
Summon the Shambling Horde.
As an action gain a wound to summon shadow minions equal to the difference between your current amount and your maximum. They are summoned in spaces adjacent to you.
Level 15
Master of Death.
Whenever you would gain one or more wounds you may reduce the amount of wounds gained by sacrificing that many shadow minions. This ability cannot prevent wounds gained when you Summon the Shambling Horde.
Lichdom.
You are undead and do not need to breathe, eat, or sleep and are immune to the Frightened and Poisoned conditions.