Void, the Godhand's Thumb

Regeneration. Void regains 25 hit points at the beginning of his turn.

Spell Resistance. Void has resistance to damage dealt by spells.

Legendary Resistance (3/Day). If Void fails a saving throw, he can choose to succeed instead.

Causal Awareness. Creatures attempting to attack Void do so with disadvantage, and Void has advantage on saving throws.

Eldritch Mind. Void automatically succeeds on Intelligence checks and saving throws.

Innate Spellcasting. Void can innately cast the following spells (DC 24, +18 to hit), requiring no verbal, somatic, or material components. 

• At will: detect thoughts, teleport, confusion, reverse gravity, silent image, dimension door, telekinesis
• 3/Day each: feeblemind, power word kill, weird, dominate monster, antimagic field, mirage arcane

Mind Probe. Void targets a creature within 300 feet. Void does not need to be able to see the creature, he only needs to know a creature is there, such as described by the detect thoughts spell. That creature must make a DC 22 Intelligence save; on a failure, Void understands their personality traits, ideals, bonds, and flaws. Additionally, Void can read their surface thoughts for one day.

Spatial Distortion. Each creature within 300 feet of Void must make a DC 22 Dexterity saving throw. On a failure, Void teleports them to an unoccupied space within a 300 foot radius of himself. 

Teleport. Void teleports up to 600 feet into an unoccupied space he can see.

Invocation of Doom. This action can only be activated during the Eclipse event. Void chooses up to one hundred creatures within 600 feet of himself; they become marked by the Mark of Sacrifice. A creatures' very soul is affected by the Mark, and it cannot be removed by any means. While marked, all Undead, Fiends, and Aberrations are aware of the marked creatures' location while it is within 120 feet of them. These creatures are drawn to the Mark, and seek to destroy the Marked person. 

Summon Apostles (1/Day). Void calls upon the legions of horrors at his command. 1d4 hezrous and 2d4 otyughs appear in unoccupied spaces within 120 feet of Void. These creatures are Aberrations, have no subtypes, and take on horrifying humanoid features, granting them the dybbuk's Violate Corpse ability (DC 18). Instead of violating a corpse, however, they simply make their body do something unnatural. Void can telepathically command these creatures as a free action. These creatures act right after Void in the initiative order.

Invoke Despair. Void telepathically projects images of the horrors of existence onto the mind of a creature within 120 feet of himself. That creature must make a DC 22 Wisdom saving throw; on a failure, they fall prone and become stunned. They may make this save at the end of each of their turns. On a success, that creature is immune to this ability for 24 hours.

Dimensional Mastery (1/Day). Void can open a portal to any plane in the multiverse. As an action, Void can open a portal up to 30 ft in diameter to any plane. This portal can be opened to any location on the chosen plane. This portal only functions from one side. The portal closes only after Void dismisses it or he dies.

Claw. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 18 (4d6 + 4) slashing damage, plus 18 (4d8) necrotic damage.

Spatial Manipulation. When Void is hit by an attack but before damage is rolled, he can use his reaction to choose new targets for the attack. The attack is treated as though it originated from his space. The creature that made the attack must then roll to hit against the new target. Ranged attacks are made with disadvantage. 

Void can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Void regains spent legendary actions at the start of his turn.

Reaction (Costs 1 Action). If Void has already used his reaction, he may take another reaction this round.

Teleport (Costs 1 Action). Void uses his Teleport action.

 Claw (Costs 1 Action). Void makes a Claw attack.