Valuron Bonyishma

Corrupting Aura: Any creature that is within 30ft of Valuron on the start of their turn must make a Sanity saving throw on a fail they lose 1 point from the sanity ability score. At the start of Valurons turn they take 2d10 Necrotic damage plus 12 ignoring resistances.

Other worldly aid: When ever Valuron casts a spell he may take the attack action with his bonus action.

Regen: Valuron regenerates 15 hit points at the start of its turn unless it takes radiant damage.

Eyes of the Elder lord: Any creature within a 20ft cone infront of Valuron may not cast spells of 5th level or lower, unless Valuron lets it happen. 

Valuron has the ability to cast the following spells: DC 24, +15 to hit with spell attacks
At-will Cantrips: Eldritch Blast, Encode Thoughts, Spare the dying
At-will 1st lvl 4 times each per long/short rest: Armor of Agathys, Arms of Hadar, Cause Fear, Comprehend Language, Find Familiar, Inflict wounds
At-will 2nd lvl 2 times each per long/short rest: Crown of Madness, Darkness, Detect Thoughts, Enthrall, Knock, Misty Step, Nystuls Magic Aura, Shadow Blade
3rd lvl spells, 2 spell slots: Animate Dead, Bestow Curse, Counterspell, Dispel Magic, Hunger of Hadar, Life Transference, Vampiric Touch
4th lvl spells, 1 spell slot: Blight, Evards Black Tentacles, Greater Invisibility, 
5th lvl spells, 1 spell slot: Immolation 

Wrath of all that came before (This action becomes avaliable when Valuron Bonyishma is dropped to less than 100 damage.): Valuron may cast Time Stop and recharge this ability from a d10 on a roll of 1

Multi-Attack: 2 Defiler blades, 1 Ravens grasp 
Defilers Blade:+15 to hit, reach 5ft, one creature. Hit: 3d6 necrotic damage; 4d6 Necrotic plus 12 Damage. Upon a hit, any condition that is affect Valuron is transferred to the creature that is hit with this attack

Ravens Grasp: +12 to hit reach 10ft two creatures. Hit: 3d6 piercing damage plus 10 Necrotic damage.

Valuron has 3 legendary actions

Quickened Reflexes (costs 1): Valuron may make an attack attack action either making 1 defilers blade or cast a spell.

Hyper Extensive Adaptation (costs 1): Regenerates 10 hit points, and turns invisible.

Movement (costs 1): May move his speed.

Unearthly Hatred (costs 2): With the fueling rage of an otherworldly being that surges its way through Valurons body giving him the ability to summon 1 Death Slaad or 2 blue and 1 Green Slaad