Lightning, Security Sergeant — ruling 1

You pay all costs and follow all timing rules for cards played this way. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty and only if you have an available land play remaining.

Lightning, Security Sergeant — ruling 2

If another player gains control of Lightning, you won't be able to play any of the exiled cards, even if you later regain control of Lightning. Similarly, if Lightning leaves the battlefield and later returns, you won't be able to play the cards that were exiled the first time it was on the battlefield since it's a new object.

Lightning, Security Sergeant : règles, fonctionnement et interactions (MTG)

Lightning, Security Sergeant is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Menace (This creature can't be blocked except by two or more creatures.) Whenever Lightning deals combat damage to a player, exile the top card of your library. You may play that card for as long as you control Lightning.

How it works : Lightning, Security Sergeant

Original English text — Wizards of the Coast / Scryfall

#1June 6, 2025· Wizards of the Coast
You pay all costs and follow all timing rules for cards played this way. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty and only if you have an available land play remaining.
No other card is named in this ruling.
#2June 6, 2025· Wizards of the Coast
If another player gains control of Lightning, you won't be able to play any of the exiled cards, even if you later regain control of Lightning. Similarly, if Lightning leaves the battlefield and later returns, you won't be able to play the cards that were exiled the first time it was on the battlefield since it's a new object.
No other card is named in this ruling.