This mindflayer has been experimented on to develop its arcane powers, and has gone completely insane, bent on joining every living thing into its cult of arcane destruction.
Magic resistance: advantage on saves vs spells and magic effects
Psionics: (spell save dc15, +7 to hit w/spells) at will: detect thought, levitate
1/day: dominate monster, plane shift (self)
Corrupted Serene Mind Thrall
Tentacles: Melee, +7 to hit, reach 5ft, one creature.
Hit: 15(2d10+4) psychic dmg. If target is med or smaller, is grappled (escape DC15), must make dc15 int save or be stunned until grapple ends
Extract Brain: melee, +7 to hit, reach 5ft, one humanoid grappled by mindflayer. Hit 55 (10d10 piercing). If reduces target to 0, target is killed by brain devouring
Mind Blast (recharges 5-6): emits psychic energy in 60ft cone. Each creature DC15 int save or take 22(4d8+4) psychic dmg and 1min stun. Creature can repeat save at end of each turn to end the effect on a success
Cantrips: blade ward, dancing lights, mage hand, shocking grasp
1st level (4 slots): command, disguise self, shield, sleep
2nd level (3 slots): blur, detect thoughts, hold person
3rd level (3 slots): clairvoyance, lightning bolt, sending
4th level (3 slots): confusion, hallucinatory terrain
5th level (2 slots): telekinesis, wall of force
On every turn, rolls a d20 and take the following actions:
1-5: Mindflayer takes no action but to emit a piercing mental shriek, in a 50ft sphere. All creatures make DC10 int save to avoid being stunned for 1 round and take 1d4 psychic damage
6-10: The Mindflayer casts command on the nearest humanoid, and commands it to start carving qualith words into its skin. DC 10 wis save to resist.
11-15: The Mindflayer takes 1d8 psychic damage from itself
16-19: The Mindflayer heals itself for 1d8
20: Mindflayer rolls on the wild magic table for 1 effect