Cards And Zones
When Does Deathknell Happen?
Deathknell triggers only when its own permanent is killed and sent to the Trash.
RiftPal explanation · Answer first
The short answer
DeathknellAn ability that triggers when its own permanent is killed and sent to the Trash. Replacing that death with something else prevents the Deathknell from happening.View in Glossary means "When I die." It happens when its PermanentA Main Deck game object that remains on the board after being played. Unit and Gear are permanent types. Runes, battlefields and legends are not permanents simply because they stay on the board.View in Glossary is killed and sent to the TrashA player's off-board zone for cards that are killed or discarded and spells that finish resolving, unless an effect changes their destination. Its cards are public information and their order does not matter.View in Glossary . If a replacement saves it from that death, its Deathknell does not happen.
RiftPal explanation
How it works
Card reference
Watchful Sentry
Use the PermanentA Main Deck game object that remains on the board after being played. Unit and Gear are permanent types. Runes, battlefields and legends are not permanents simply because they stay on the board.View in Glossary 's location and relevant details from just before it left the board when handling its DeathknellAn ability that triggers when its own permanent is killed and sent to the Trash. Replacing that death with something else prevents the Deathknell from happening.View in Glossary . The game records its own-death trigger before moving it to the TrashA player's off-board zone for cards that are killed or discarded and spells that finish resolving, unless an effect changes their destination. Its cards are public information and their order does not matter.View in Glossary , so those details are still available.
Unit
Watchful Sentry
[Deathknell] — Draw 1. (When I die, get the effect.)
If a KillSend a permanent directly from the board to its owner's Trash, either by an instruction or because the rules find it should die.View in Glossary instruction is replaced with something else, such as a Recall, remove the DeathknellAn ability that triggers when its own permanent is killed and sent to the Trash. Replacing that death with something else prevents the Deathknell from happening.View in Glossary trigger from the ChainAn off-board zone that holds cards and abilities during the process of playing them. Cards and abilities on it are public information.View in Glossary . If a PermanentA Main Deck game object that remains on the board after being played. Unit and Gear are permanent types. Runes, battlefields and legends are not permanents simply because they stay on the board.View in Glossary has several Deathknell abilities, each triggers separately and its controller chooses their order on the Chain.
In practice
Example
Your unit has lethal damage. Normally it is killed and sent to the Trash, so its Deathknell happens. If an effect replaces that death by healing and recalling it, the unit survives and its Deathknell does not happen.