The Mirrorfiend is a Daemon Engine of Tzeentch from the setting of Black Crusade, created by imprisoning a Lord of Change inside a giant mechanical beetle, which can scurry across the harshest terrain on mechanical legs or soar through the air on wings of light. Native to the city of Tarnor on the Tzeentch-worshipping renegade world of Q'Sal, these terrible engines make use of potent psychic powers to cripple, maim and mutate victims before rending them apart with giant daemonflesh pincers. Their most lethal ability is their Mirror of Souls, a psychic aura that attacks the resolve of those who look at it, its mirror-like surface displaying all their doubts, fears and regrets for them to see in hideous lividity. Worse, this aura is especially powerful against those who worship the God-Emperor of Mankind, as it resolves on feeding on their most subconscious fears and doubts regarding his existence, divinity or very life.
You wish there were official rules for a unit this badass!
In Black Crusade
Mirrorfiend: WS: 39 BS: 35 S: 48 T: 54 Ag: 38 Int: 57 Per: 50 WP: 62 Fel: 45 Inf: --
Movement: (Ground) 14/28/42/84, (Flying) 10/20/30/60
Total TB: 11
Armor: Machine Trait (27 all)
Crew: Daemonic Essence
Skills: Awareness (Per) +20, Dodge (Ag), Invocation (Wp) +20, Psyniscience (Wp) +20
Talents: Ambidexterous, Independent Targetting, Two Weapon Wielder (Melee & Ranged)
Traits: Daemon Engine (6), Fear (3), Flyer (10), Machine (27), Mirror of Souls, Psy Rating (6), Psyker, Quadruped (2), Warp Shroud
Weapons: Head-Mounted Daemon Pincers (4D10+20, R, Pen 2, Warp Weapon)
Psychic Powers: The Mirrorfiend has access to all the Unaligned, Tzeentch and Telepathy powers. As a Half Action, it may use any two powers every turn it does not engage in close combat, but one power if engaged.
Daemon Engine: The creature has the combined effects of From Beyond and The Stuff of Nightmares, making it immune to Fear, Pinning, Stunning, Insanity, Poison and Disease. It cannot be controlled by Psychic Powers that affect the mind. It gains a Toughness bonus equal to the number in parentheses, which can be negated by force weapons, holy/sanctified weapons, and direct damage psychic powers.
Mirror of Souls: Characters attempting to engage a Mirrorfiend in close combat must make a Challenging (+0) Willpower Test (Sanctioned Psykers or characters "tied to the Ecclesiarchy" take a -10 penalty to this check). On a Success, the character loses a Half Action but may continue normally. On a Failure, the character is Stunned for 1D5 turns.
Warp Shroud: The daemon engine has a forcefield of sorcerous energy, granting it +2D10 points of armor against all harm other than Blessed/Sanctified/Force Weapons and Psychic Powers. When the Daemon Engine takes a Critical Hit, there is a chance of losing the Warp Shroud dependent on the D10 roll for the Critical Hit impact. A Distracting Blow (result of 01-3) requires rolling a D10; on a 6 or less, the Daemon Engine loses its Warp Shroud. An Ablative Strike (result of 4-6) requires rolling a D10; on an 8 or less, the Daemon Engine loses its Warp Shroud. On a Penetrating Hit (result of 9), the Warp Shroud is automatically lost.
Homebrew 40K Stats
Keep in mind that this is a case of /tg/ getting shit done, and thusly not official in any way at all. Also, people are likely to come along and tweak this stuff all the time.
The Mirrorfiend is a Heavy Support choice for a Chaos Space Marine army that costs 155 points.
Mirrorfiend Stats: WS: 4 BS: 3 S: 5 FArmor: 14 SArmor: 13 RArmor: 11 I: 4 A: 2 HP: 4
Unit Type: Vehicle (Walker, Flyer, Hover)
Wargear: Two Lightning Claws, Daemonic Possession
Special Rules: Daemon, Fleet, It Will Not Die, Mirror of Souls, Psychic Pilot (Mastery Level 3)
Mirror of Souls: All enemy units with a model within 12" of a Mirrorfiend suffer -3 Leadership and -3 Initiative, to a minimum of Leadership 1 and/or Initiative 1.
Psychic Powers: May generate powers from the Tzeentch or Telepathy psychic disciplines.