Sidisi, Brood TyrantHow it works & interactions with other cards

Harnessing the Mill

Sidisi has two distinct abilities that work in tandem. The first is a triggered ability that occurs whenever she enters the battlefield or attacks, forcing you to mill three cards. The second is a triggered ability that creates a 2/2 black Zombie creature token whenever one or more creature cards move from your library to your graveyard. Importantly, this second ability triggers regardless of how the cards got there, whether through Sidisi's own mill effect or other card abilities.

Step-by-Step Resolution

When Sidisi enters the battlefield or attacks, her first ability is put onto the stack. When it resolves, you take the top three cards of your library and put them into your graveyard simultaneously. After they are moved, the game checks if any creature cards were among them. If at least one creature card was milled, Sidisi's second ability triggers. This trigger then goes on the stack and, when it resolves, you create exactly one Zombie token.

One Trigger or Many?

A common mistake is assuming you get a Zombie for every creature card milled. Sidisi's ability specifies 'one or more' creature cards. Because all cards from a single mill effect (like Sidisi's mill three) move at the same time, they only count as one event. To get multiple Zombies in a single turn, you need to initiate multiple separate instances of milling or discarding from the library.

Strategic Timing

Because Sidisi triggers on both entry and attack, she provides immediate value. You want to play her when you have ways to protect her or when your library is rich with creatures. Remember that her token-generating ability triggers even if she is no longer on the battlefield, provided the mill event that caused the trigger began while she was still present.

Interaction examples

The Entry Trigger

Sidisi, Brood TyrantSolemn SimulacrumEternal Witness

You cast Sidisi, Brood Tyrant. When she enters, her ability mills three cards. If those three cards happen to be Solemn Simulacrum, Eternal Witness, and a Forest, Sidisi's second ability triggers once because 'one or more' creatures entered the graveyard. You create one 2/2 black Zombie creature token.

An Empty Mill

Sidisi, Brood Tyrant

Sidisi, Brood Tyrant attacks, triggering her mill ability. You mill three lands. Because zero creature cards were put into the graveyard from the library, her second ability does not trigger, and no Zombie token is created.

Multiple Mill Events

Sidisi, Brood Tyrant

If you have an effect that tells you to 'Mill one card, then mill one card,' and both are creatures, Sidisi would trigger twice. However, with her own ability, she mills three cards at once. Even if all three are creatures, the 'one or more' rule applies to that single event, resulting in only one Zombie token.