Undead General

You imbue one undead creature that you control with enhanced sentience and, if required, the ability to speak one language of your choice, such that you can delegate the majority of command to it. When you cast this spell on a creature with an Intelligence less then 13, it's Intelligence becomes 13 for the duration. You may explain an objective or set of objectives for the general to achieve. These may be as abstract and complex as you wish, and the spell's power compels the target to understand your orders.

Undead creatures under your control obey the general as if it were you. You can give orders to your Undead normally, superseding the orders of the general (in the event you have an undead lieutenant and general simultaneously giving orders, the general's orders will be prioritized)

On each of its turns thereafter, the general can use a bonus action to mentally command any of your undead within a 2 kilometer radius, it will use this ability whenever it can in pursuance of the objective(s) you set. It can command any or all of them at the same time, issuing the same command to each one. If it issues no commands (such as if it is incapacitated or out of range), the subordinates only defend themselves against hostile creatures. Once given an order, a creature continues to follow it until its task is complete.

An undead general is a force to be reckoned with while on the field of battle, undead under your control that are within 120 feet of it can add your proficiency bonus to their armor class, and saving throws, as well as their attack and damage rolls (this feature overrides the benefits that a lieutenant gives and does not stack with it, an undead general is always subject to this feature).
After finishing a long rest, the general grants all undead under your control temporary hit points equal to your proficiency bonus times your spell casting modifier.

Once created, undead generals no longer need to be within range for you to maintain control of them (IE: via an Animate Dead spell), or the undead under their command (undead you control within 60 ft. of the Lieutenant), so long as they are on the same plane of existence as you, you need only spend a spell slot to do so.

If you lose control of the general, or the creature dies, this spell ends.

You may only control one undead general at a time.