School of Necromancer (an idea, advice wanted)

A necromancer who walks the line between scholar and grave-robber, binding the souls of the dead to their will. Starting with a single crude thrall stitched together from a fallen corpse, you grow into a master of the undead — raising armies of zombies and skeletons, becoming resistant to the forces of death itself, and ultimately commanding a consecrated tombstone that lets you raise the dead at will.

Level 3: Necromancy Savant

Choose two Wizard spells from the Necromancy, each of which must be no higher than level 2, and add them to your spellbook for free.

In addition, whenever you gain access to a new level of spell slots in this class, you can add one Wizard spell from the Necromancy school to your spellbook for free. The chosen spell must be of a level for which you have spell slots.

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Level 3: Unholy Covenant

At 3rd level, you can bind the soul of a dead creature to your service. Choose a visible corpse of a humanoid or beast that is Medium or smaller and was CR ½ or lower in life.

Statistics. The bound creature becomes undead and keeps its statistics from life, with these changes:

• Its hit point maximum becomes half its normal maximum, plus your proficiency bonus (minimum 3).
• It loses all special traits and unique actions (such as Pack Tactics or Pounce), but keeps its speeds, ability scores, skills, senses, languages, and attack actions. (unsure if i should remove this for uniqueness or keep it for balance sake)
• If its Multiattack would grant additional attacks, it instead makes one attack that deals an extra 1d4 necrotic damage per additional attack the Multiattack would have granted.

Mind and memory. The creature remembers nothing of its life. It can speak only if it could in life, and only in languages you know. If it could cast spells in life, it can still cast those spells, but only using your spell slots — doing so expends one of your slots of the appropriate level, as if you had cast the spell yourself. You also cannot make them upcast spells. (maybe i will nerf this to cantrips only, or only spells you know)

Control. The creature acts on your turn, immediately after you. As a bonus action, you can command it to attack; otherwise, it uses its action to Dodge.

Limits. You can have only one creature bound this way at a time. Using this feature again while you have a bound creature kills the old one and lets you bind the new corpse immediately, without the waiting period below. If your bound creature dies any other way, you can't use this feature again until 24 hours have passed.

At 6th level, the CR limit increases to 2. Using this feature on a corpse that isn't a Medium or smaller humanoid or beast instead lets you create a zombie or skeleton of your choice, which isn't affected by the hit point reduction.

Level 6: Undead Thralls

At 6th level, you add Animate Dead to your spellbook if you don't already know it. When you cast it, you can target one additional corpse or pile of bones, raising an extra zombie or skeleton.

General benefits. Any undead you create with a necromancy spell, or with Unholy Covenant, gains the following:

• Its hit point maximum increases by an amount equal to your wizard level.
• It adds your proficiency bonus to its weapon damage rolls.

Covenant thrall benefits. Your Unholy Covenant thrall specifically also gains:

• You can command it to Dash, Disengage, or Hide using your reaction instead of your bonus action.
• As an action, you can speak through it and see through its senses.

Level 10: Inured to Undeath

Beginning at 10th level, you've spent so much time among the undead that you've become inured to some of their worst effects:

• You have resistance to necrotic damage.
• Your hit point maximum can't be reduced.
• If you would be reduced to 0 hit points by an attack, you can use your reaction to have your Unholy Covenant thrall die in your place instead.

Level 14: King of Worms

Beginning at 14th level, once per long rest, you can spend 1 minute performing a ritual to raise a tombstone (AC 15, HP 50; immune to poison and psychic damage; resistant to necrotic damage) on a patch of open ground within 30 feet of you.

While the tombstone stands:

• As a bonus action, you can turn a corpse within 30 feet of the tombstone into a zombie or skeleton — either one you just reduced to 0 hit points, or one already present that you touch. This requires no spell slot and doesn't count as casting Animate Dead.
• You can't have more than three undead created this way active at once. Raising a fourth causes the oldest to die immediately.
• Animate Dead now keeps its undead under your control for 48 hours instead of 24.

The tombstone doesn't act or animate corpses on its own — you must spend the bonus action each time. It lasts 24 hours or until destroyed, then collapses; any undead raised through it die when it does. It doesn't raise your overall undead-control limit beyond what you'd normally have.