Ancient Beast (1/2 Repaired)

Sacrificial repair. Whenever the Ancient Beast places humanoid skin on it skeletal structure one quarter of the covered area is returned to its original state.

Spellcasting. The Ancient Beast is a 5th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 16, +7 to hit with spell attacks). The Ancient Beast has following wizard, warlock, druid spells prepared:
Cantrips (at will): fire bolt, eldritch blast, starry wisp, poison spray
1st level (4 slots): detect magic, magic missile, chromatic orb 
2nd level (3 slots): acid arrow, invisibility, mirror image
3rd level (3 slots): counter-spell, dispel magic
4th level (3 slots): dimension door, conjure minor elemental, ice storm
5th level (3 slots): scrying, cone of cold

Multiattack. Ancient beast uses attacks twice with its claws

Rending Claw. Melee weapon attack:  +7 to hit (2d10 +6) Slashing damage

Control Creature. Any singular humanoid creature (of DMs choice)in 200 ft must succeed a DC 16 wisdom saving throw or be under the control of this creatures commands. (if in battle, at the end of every turn the creature can reroll their saving throw) On a successful save the target creature is immune to this creatures effect for 1 hour

Menacing Glare. Any creature within sight of the Ancient Beast must succeed a DC 14 Wisdom saving throw or lose 2d8 to all damage rolls and all attacks are with disadvantage.

Unkillable. Upon reaching 0 Hp the Ancient beast reverts to an inanimate skull (animal of DM choice) which emanates a manipulative energy within a 20 ft area around it.
Once fresh humanoid blood makes contact with the skull, the Ancient Beast is revived in its recently revived state.

Elemental Outrage (Costs 2 Actions). The Ancient Beast conjures three elementals (of the same or different elements) to fight alongside it.