Armor of Gurdians (5e Equipment)
From D&D Wiki
Armor (plate), legendary (requires attunement)
This armor is said to have been the product of a mage who used his talents in necromancy to help the common people. The armor is a blue and black design with a Cyan crystal in the middle of the chest. After killing an enemy their soul is sucked into the crystal and stuck indefinitely till used. While wearing this armor, the wearer is immune to force damage and has resistance to necrotic damage.
Souls- You can use souls you collect to create undead minions or to cast spells. Whenever you kill a creature that is not of undead or construct type, you gain 1 soul. You can only hold 50 souls in the crystal at once. If you kill another enemy while you have 50 souls, you must make DC 19 Constitution saving throw or the armor will break and release all the souls back to their owners if the bodies are on the same plane of existence as the armor.
Undead- When creating undead, you don't require a body just a soul and the creature "warps" into existence. This process takes 10 minutes to warp the summoned minion. The undead are friendly to you and your companions, having their own turns and only taking orders from you. They remain under your control for 2 hours or when they reach 0 hit points.
Skeleton: 3 Souls
Zombie: 6 Souls
Ghoul: 12 Souls
Specter: 24 Souls
Wight: 34 Souls
Ray of Enfeeblement: 5 Souls
Inflict Wounds: 15 Souls
Spirit Guardians: 25 Souls
Arcane Sword: 40 Souls