Kai Winn, Faithless LeaderHow it works & interactions with other cards

What it does

Kai Winn has a replacement effect that functions as she enters the battlefield. You must choose a nonland card name. Once she is on the battlefield, her triggered ability monitors the game for any time an opponent casts a spell with that name or activates an ability from a source with that name. Each time they do, that player loses 3 life.

How it resolves step by step

First, as Kai Winn enters, you choose the name; this does not use the stack and cannot be responded to once she begins resolving. Second, the game checks for triggers. If an opponent casts a spell or activates an ability (other than mana abilities) of the chosen source, Kai Winn's ability triggers and goes on the stack on top of that spell or ability. The 3 life loss will happen before the opponent's original action resolves.

Common Mistakes

A common error is naming a land card. Kai Winn specifically states you must choose a nonland card name. Additionally, remember that Kai Winn does not stop the spell or ability from happening; it only punishes the player with life loss. If the opponent has enough life to pay the price, they can still resolve their effects.

When to play it

Kai Winn is most effective in formats where decks rely on specific four-of cards or legendary finishers. She is also a strong choice against decks that use 'sacrifice outlets' or repeated activations. Dropping her early allows you to tax early-game setup spells or late-game win conditions.

Interaction examples

Taxing a Mana Source

Ornithopter of Paradise

If you name Ornithopter of Paradise as Kai Winn enters, and your opponent later activates the Ornithopter's mana ability, Kai Winn's ability will trigger. While mana abilities don't use the stack, Kai Winn's triggered ability does, forcing the opponent to lose 3 life for the mana they just generated.

Punishing Death Triggers

Blood Artist

Note that Blood Artist features a triggered ability, not an activated one (it uses 'Whenever' instead of a colon). If you name Blood Artist, your opponent will lose 3 life when they cast the spell. However, they will NOT lose life from Kai Winn when the Blood Artist's death-trigger goes off, as Kai Winn only punishes activated abilities.