Mind Flayer Mastermind
Medium aberrant humanoid
Level 18 Elite Controller (Leader) XP 4000

Initiative +12        Senses Perception +18; Darkvision
Psychic Static (Psychic) aura 10; while the mind flayer mastermind is not bloodied, enemies in the aura take a -2 penalty to Will defense.
HP 324; Bloodied 162
AC 33; Fortitude 33, Reflex 33, Will 35
Saving Throws +2
Speed 7
Action Points 1

(⚔) Tentacles (standard, at-will)

+21 vs AC; 3d6+3 damage, and the target is grabbed (until escape).

⚔ Bore into Brain (standard, at-will) ✦ see text

Grabbed or stunned target only; +21 vs Fortitude; 4d10+3 damage, and the target is stunned (save ends). If this power reduces the target to 0 hit points or fewer, the mind flayer mastermind can either devour its brain or turn it into a thrall (see below):
    Devour Brain (Healing): The mind flayer mastermind devours the target's brain. The target is killed instantly, and the mind flayer mastermind regains 25 hit points.
    Create Thrall (Charm): The target is dominated (no save) and regains enough hit points to restore it to its bloodied value. As a thrall, the target is immune to the mind blast power of mind flayers and gains a +5 bonus to its Will defense while within 10 squares of the controlling mind flayer mastermind. The target is no longer dominated and no longer a thrall once the controlling mastermind dies.

ᗕ Mind Blast (standard, recharge ⚄⚅) ✦ Psychic

Close blast 5; mind flayers and their thralls are immune; +21 vs Will; 3d8+7 psychic damage, and the target is dazed (save ends). Miss: Half damage, and the target is not dazed.

➶ Enslave (standard, recharge ⚄⚅) ✦ Charm

Ranged 10; +21 vs Will; the target is dominated (save ends). While dominated, the target is immune to the mind blast power of mind flayers and gains a +5 bonus to its Will defense while within 10 squares of the controlling mind flayer mastermind. The mastermind can use enslave only on one creature at a time.

✻ Illusion of Pain (standard, recharge ⚄⚅) ✦ Illusion, Psychic

The targets imagine that the area is filled with writhing, barbed tentacles; Area burst 1 within 10; targets enemies within the burst; +27 vs Will; 2d10+6 psychic damage, and the target takes ongoing 10 psychic damage and is immobilized (save ends both).

Cradle of the Elder Brain (immediate interrupt, when attacked; recharge ⚄⚅) ✦ Teleportation

The mind flayer mastermind teleports 20 squares.

Interpose Thrall (immediate interrupt, when targeted by a melee attack; at-will)

The mastermind redirects the attack to an adjacent thrall.

Alignment Evil        Languages Deep Speech, telepathy 10
Skills Arcana +18, Bluff +21, Insight +18, Intimidate +21
Str 11 (+9)      Dex 16 (+12)      Wis 18 (+13)
Con 18 (+13)      Int 18 (+13)      Cha 24 (+16)

Published in Monster Manual, page(s) 188, Dungeon Delve, page(s) 95.