In a combat, do deathknell effects happen before or after a unit is healed after combat ends?

Deathknell effects occur before units are healed at the end of combat.

According to the rules governing combat and cleanup (Rule 322), the process for handling units that have taken lethal damage is structured to ensure Deathknell abilities trigger and are processed before the units are removed and the board state is finalized.

The sequence is as follows:

1. Triggering Deathknell: During the "Handle outstanding board state" step of the cleanup (Rule 322.3), all units with non-zero damage equal to or exceeding their Might that possess Deathknell abilities trigger those abilities. These triggers are added to the chain as "Pending Items."
2. Killing Units: Immediately following the triggering of Deathknell abilities, units with lethal damage are killed and placed in the trash (Rule 322.4).
3. Finalizing Chain: Later in the cleanup process (Rule 322.12), any pending items on the chain—including the Deathknell effects triggered in step 1—are finalized and resolved.
4. Healing: Healing occurs as part of the cleanup process (or at the end of the turn). Because Deathknell triggers are added to the chain and finalized as part of the cleanup sequence, they resolve while the damage is still technically marked on the units (or just after they have been moved to the trash), ensuring the effects occur before the final healing window clears all remaining damage from the board.

In short, Deathknell abilities are triggered by the state of the unit before it is removed and before the final healing occurs.