The Cyber-Controller

Mana cost: {X}{U}{U}{B}
Type: Legendary Artifact Creature — Cyberman
Power / toughness: 3 / 3
Set: Doctor Who #996 (rare)

When The Cyber-Controller enters, each opponent mills X cards. Put all creature cards milled this way onto the battlefield face down under your control. They're 2/2 Cyberman artifact creatures.
Other artifact creatures you control get +1/+1.

The Cyber-Controller has 4 printings, first in Doctor Who (2023). EDHREC ranks it #8,298 among Commander cards. It appears most in Missy decks (1,799 on EDHREC). 1 public deck on TCG runs it. It has 5 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: not legal
modern: not legal
pioneer: not legal
standard: not legal
brawl: not legal

Public decks that run The Cyber-Controller

Masters of Evil - Doctor Who, led by Davros, Dalek Creator

Commanders that run The Cyber-Controller most

Deck counts from EDHREC.

Often played with The Cyber-Controller

Cards that show up in the same decks on EDHREC.

Rulings

2023-10-13: Double-faced permanents that are already on the battlefield can't be turned face down this way. However, a double-faced card can be put onto the battlefield face down from another zone this way.
2023-10-13: If, for any reason, the face-down creature is turned face up, the effect making it a Cyberman ends. It will be whatever is printed on the card.
2023-10-13: The player who controls a face-down permanent may look at it at any time. Notably, if the cards were put on the battlefield face down from another player's library, the player that owns them does not get to look at those cards.
2023-10-13: If the face-down card has a morph ability, its controller may turn it face up by paying the associated morph cost.
2023-10-13: Each creature turned face down this way or put onto the battlefield this way is a 2/2 Cyberman artifact creature with no name and no color.