Create Grave Guardian

Choose any number of corpses in the range of the spell. The corpses all band togethed, fused by necromantic energies, to create one powerful entity under your control.

The emerged grave guardian takes on the stats of any generic Undead monster with CR up to the combined CR of all the creatures you have used as material components of the spell, but not exceeding CR 6. The guardian cannot use any feature that enables it to raise, command, order, summon or control other creatures, if it had any, and loses all legendary and lair actions, if it had any. It also loses access to the Animate Dead and Create Undead spells, if it had access to those. The guardian obeys your commands(no action required from you) and will try to complete any command to the best of its ability. You can only issue new commands to the guardian when you are within 120 feet of it (if you control multiple guardians, you can command any or all of them at the same time). You decide what action the guardian 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 guardian only defends itself against hostile creatures. Once given an order, the guardian continues to follow it until its task is complete. 

The guardian is under your control for 24 hours, after which it stops obeying any command you have given it. To maintain control of the guardian for another 24 hours, you must cast this spell on the guardian before the current 24-hour period ends. This use of the spell reasserts your control over the guardian you have animated with this spell, rather than animating a new one. The CR limit for reassetting control over guardian applies as well.

At Higher Levels. When you cast this spell using a 7th-level spell slot, the CR limit for creating and reasserting control over the guardian increases by 1 for every spell level above 6th.