Aliturim the Corrupted

Subiecti ad Voluntatem. All creatures / beings that were summoned or enter into a 325 ft radius from Aliturim, must make a DC 21 wisdom saving throw or on a failed save gain the effect subjugation. On a successful save creatures / being are immune to subjugation for 24 hours. Creatures / beings with the effect subjugation will refuse the orders of their original summoner and will obey all commands made by Aliturim. The effect ends once the creature / being leaves the 325 ft radius or once the creatures original duration is up. 

Atrox Praesentia. All creatures who gaze upon Aliturim must make a DC 13 wisdom saving throw. On a failed save, the creature gains the status effect frightened until the end of Aliturim's next turn. On a successful save, the creature is immune to Atrox Praesentia for 1 hour.

Fortis Animus. Aliturim can concentrate on up to 11 spells at once. Concentration can not be broken by taking damage or failing a constitution saving throw.

Resistentia ad Magica. Aliturim has advantage on saving throws against spells and other magical effects.

Sanatio. Aliturim regains 20 hit points at the start of it's turn. If it takes radiant damage, this trait doesn’t function at the start of it's next turn. Aliturim dies only if it starts it's turn with 0 hit points and doesn’t regenerate.

Fabuloso Resistentia (3/Day). If Aliturim fails a saving throw, it can choose to succeed instead.

Voluntas Multorum. Aliturim can cast any spell below 9th level in one turn. Any spell requiring more then one caster can be casted by just Aliturim, however the spell will take as many turns as 1/2 the casters required.

Spellcasting. Aliturim is a 28th-level spellcaster. Its spellcasting ability is wisdom (spell save DC 24, +19 to hit with spell attacks). Aliturim has the following spells prepared:

Cantrips (at will): Infestation, Acid Splash, Poison Spray

1st level (7 slots): Arms of Hadar, Hail of Thorns, Entangle

2nd level (6 slots): Healing Spirits, Misty Step, Summon Beast

3rd level (6 slots): Hunger of Hadar, Summon Lesser Demon, Spirit Guardian

4th level (6 slots): Black Tentacles, Guardian of Faith, Summon Elemental

5th level (6 slots): Conjure Elemental, Infernal Calling, Insect Plague

7th level (4 slots): Conjure Celestial, Teleport

8th level (4 slots): Incendiary Cloud, Tsunami

9th level (3 slots): Weird, True Resurrection

10th level (2 slots): Summon Elemental Spirits

11th level (1 slot): Wrath of the Ancients

12th level (1 slot): Ascension

Multiattack. Aliturim can use one 3rd level or lower spell. It then makes two attacks: two unerring slams or one unerring slam and a 1st level spell or lower.

Unerring Slam. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage and the target is pushed up to 5 feet away from the Aliturim if it is Huge or smaller.

Plane Shift (3/Day). Aliturim casts plane shift, requiring no material components and using wisdom as the spellcasting ability. Aliturim can cast the spell normally, or it can cast the spell on an unwilling creature it can see within 60 feet of it. If it uses the latter option, the targeted creature must succeed on a DC 20 wisdom saving throw or be banished to a dimension of Aliturim's choice.

Cursed Touch. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 28 (3d12 + 9) force damage. If the target is a creature, it must succeed on a DC 23 Constitution saving throw, or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if its hit point maximum is reduced to 0.