Betrayal of Undeath

This spell creates a necrotic resonance within the target.  Choose one humanoid creature within range that you can see.  The target suffers 2d8 necrotic damage, or half that with a successful Constitution saving throw.  While the spell remains in effect, the caster can inflict necrotic damage again as a bonus action.

if the target is slain by necrotic damage while the spell is in effect, the victim’s skeleton violently erupts from their corpse as a [monster]skeleton[/skeleton] under the control of the caster (the GM has the creature's game statistics).

On each of your turns, you can use a bonus action to mentally command any creature you made with this spell if the creature is within 60 feet of you (if you control multiple creatures, you can command any or all of them at the same time, issuing the same command to each one). You decide what action the creature will take and where it will move during its next turn, or you can issue a general command, such as to guard a particular chamber or corridor. If you issue no commands, the creature only defends itself against hostile creatures. Once given an order, the creature continues to follow it until its task is complete.

The creature is under your control for 24 hours, after which it stops obeying any command you've given it. To maintain control of the creature for another 24 hours, you must cast this spell, or Animate Dead, on the creature again before the current 24-hour period ends. This use of that spell reasserts your control over up to four creatures you have animated, rather than animating a new one.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, you Inflict an additional d8 damage for each level above 4th.