School of the Overlord Necromancer

Interpretation of Pointy Hats Overlord Necromancer Subclass. 

Necromancers who focus on the creation and control of hordes of undead are often referred to as Overlords. These practitioners of the dead arts are masters at reanimating corpses in staggering numbers, which has historically made them particularly useful in armed conflict. After all, the armies of the dead do not need to breathe, eat, or rest, and one powerful Overlord can command hundreds of necromantic thralls at once. This martial, bloody history has tainted the already ugly reputation of this particular type of Necromancer. Still, an Overlord is as likely—or as unlikely—as any other Necromancer to use their powers for evil. Overlords have razed entire nations to the ground, but they have also raised the dead to protect the weak, to rebuild after catastrophe, and even to take care of janitorial services. The unthinking, unfeeling army of an Overlord is theirs to command for whatever purpose they see fit.

Level 3: Necrotic Vestige

Your interest in the dead and creating new life from undeath has led you to the art of Necrotic Vestiges. To create a Nectoric Vestige (required for summoning your Thrall Swarm), you must sacrifice a living creature. Once you make your sacrifice, spend 10 minutes transforming its body into a Vestige. 

When you summon your Thrall Swarm with the Vestige, it is integrated within the swarm and will be destroyed if the Swarm is reduced to 0 hit points. 

You can make an unlimited amount of Vestiges per day, but only 1 can be created at a time. 

Level 3: Thrall Swarm

You have directed your necromantic studies towards the goal of raising an overwhelming number of undead thralls using the Thrall Swarm Stat Block.

With your Vestige equipped in your off-hand, use your bonus action to summon the Thrall Swarm.

When summoned, you determine the Thrall Swarm’s appearance and can use the Swarm in Combat. In combat, your Thrall Swarm is an ally to you and your allies. It shares your Initiative count, but it takes its turn immediately after yours. It can move and take its Reaction on its own, but the only action it takes is the Dodge action unless you take a Bonus Action to command it to take an action in its stat block or some other action. If you have the Incapacitated condition, the thrall swarm acts on its own and isn’t limited to the Dodge action.

Level 6: Grim Harvest

You gain the ability to reap the life energy of dying creatures. Whenever a non-undead, non-construct creature dies within 60 feet of you, you may steal its vitality as a reaction, healing either yourself or your Thrall Swarm 1d6 + INT Mod (minimum of one) an amount of times equal to your Proficiency Bonus. You regain all expended uses when you finish a long rest.

Level 6: Undead Barricade

Your control over your army of the dead grows stronger, allowing you to use its force both offensively and defensively. While you occupy the space of your thrall swarm, you have Half Cover. When you end your turn in your thrall swarm’s space, you can halve your thrall swarm’s Speed until the end of its next turn; until then, your thrall swarm moves you when it moves.

Level 10: Undead Fortress

As your proficiency in the undead grows, parts of your Thrall Swarm become a part of your body, giving you +2 to your AC.

Additionally, while you occupy the space of your Thrall Swarm, you now have Three-Quarters Cover. Additionally, when your Thrall Swarm enters the space of a Humanoid corpse, it can consume it and integrate it into itself (no action required). Roll one of your Thrall's Hit Dice (this does not expend a Hit Die). Your thrall regains a number of Hit Points equal to the result.

Level 14: Supreme Overlord

You have mastered your role as the Overlord of Death. When you kill an enemy, your Thrall Swarm can move to the space the enemy occupied and take its attack action for free.

Alternatively, you move your Thrall to the space the enemy once occupied, imbuing it with a spell (using the spell slot) and casting it from your Thrall. 

You can use this feature an amount equal to your INT Mod, regaining all expended uses when you finish a Long Rest.