Overflow SubmatrixHow it works & interactions with other cards

Unpacking the Borg Collective

The core ability of Overflow Submatrix allows you to cast one artifact creature spell from your graveyard during each of your turns. It doesn't matter how the card got there—whether it was discarded, milled, or destroyed—it is available for deployment. However, this cybernetic resurrection comes at a cost: the creature enters the battlefield with a finality counter, meaning its next trip to the graveyard will result in exile.

Step-by-Step Resolution

First, identify an artifact creature in your graveyard during your main phase while the stack is empty. You pay all associated costs, including mana and additional costs, to cast the spell. As the spell resolves and the creature enters the battlefield, a finality counter is placed on it immediately. If the creature would later be destroyed or die, the replacement effect from the finality counter kicks in, moving the card to exile instead of the graveyard.

Important Considerations

A common mistake is forgetting that Overflow Submatrix only permits casting the spell during your turn. Furthermore, if the creature is flickered or leaves the battlefield and returns, it loses the finality counter, as it is considered a new object. Remember that finality counters only trigger upon 'dying' (moving from the battlefield to the graveyard); effects that exile the creature directly bypass the counter's replacement effect.

Strategic Deployment

You should use Overflow Submatrix to recur creatures with powerful 'enters' or 'when cast' abilities. Because the finality counter only exiles the card when it dies, you can still get full value from enter-the-battlefield triggers. It is best used in mid-to-late game scenarios where your graveyard is populated with high-impact artifact creatures that can swing the game in your favor.

Interaction examples

Recursive Resource Gathering

Solemn Simulacrum

If Solemn Simulacrum is in your graveyard, you can cast it using Overflow Submatrix. It enters the battlefield with a finality counter, and you still get to search for a basic land. However, when it later dies, the finality counter causes it to be exiled instead of going to the graveyard, so you will still draw a card from its death trigger, but you won't be able to cast it again later.

Doubling the Collective

Roaming Throne

You can cast Roaming Throne from your graveyard via Overflow Submatrix. As it enters, you choose 'Borg'. Now, while both are on the battlefield, Roaming Throne will cause Overflow Submatrix's abilities to trigger an additional time if they were triggered abilities; however, since Submatrix uses a static permission, Roaming Throne instead benefits from its own 'Ward 2' and chosen type synergy while protected by the Submatrix's recursion potential.