Elite Spellcaster Undead

The creature of the corpse must have a CR equal to or less than a 1/5 of your wizard level rounded down, it also must be large or smaller. The creature of the corpse cannot be an undead, plant, ooze, elemental, dragon, or construct.

You carve your own insignia onto the corpse, create a chalk circle around the corpse, and with a jewel in hand you create a skeleton unlike any other. It becomes undead and its Strength score is changed to 8 unless its lower, it's dexterity score is changed to 11 unless its lower, its constitution is changed to 10 unless its lower, its Intelligence, wisdom, and charisma are changed to 12 unless it is higher. The undead's HP is half of the original creature plus your proficiency bonus. Decrease it's movement speed by 10 ft to a minimum of 20 ft, if it had any flight speed it can only lift itself 5 feet off the ground.It loses all damage immunities and resistances, it gains damage immunity to poison and damage vulnerability to bludgeoning damage. It gains dark vision up to 60 feet and it keeps any ability to use spell casting, it also keeps any features and actions it had. It loses any legendary actions, legendary resistances, and lair actions. It keeps all condition immunities and it gains condition immunity to poison. The undead can speak any language it knew in life and it keeps any proficiencies it originally had. The undead keeps any natural armor it may have had.

You can only control one undead created by this spell at a time, and you must reassert control over it every 24 hours by recasting this spell. If the undead escapes your control it opposes joining the casters party and with all its power it isolates itself from the caster and its allies. You can give a command to this creature alongside any other creature you control using a bonus action. If the undead created by this spell hits 0 HP it reverts back to the original corpse of the creature with the insignia still carved into it.