Does Ruined Rex deathknell killing Draven Audacious count as a combat death, after it leaves the battlefield to trash, gaining the Ruined Rex player a point?

Question

Accepted Answer

Yes, if Ruined Rex's Deathknell ability kills Draven, Audacious while Draven is still participating in combat, it counts as a death in combat, and your opponent will score 1 point.

### The Resolution Sequence
1. **Death Event:** Ruined Rex dies.
2. **Deathknell Trigger:** Ruined Rex's Deathknell ability triggers. According to **Rule 808.1.d.2**, the trigger is added to the chain as a **Pending Item** before Ruined Rex is moved to the trash.
3. **Chain Resolution:** The chain resolves (LIFO). If the Deathknell effect resolves while Draven is still present at the battlefield and holds his **Attacker** or **Defender** designation, the effect deals damage to Draven.
4. **Draven's Death:** If this damage is lethal, Draven is killed. Because he still holds his combat designation at the moment of his death, the death is considered to have occurred "in combat" (as established in **FAQ #8741** and clarified by the timing updates in **FAQ #8707**).
5. **Trigger Activation:** Draven's ability, *"When I die in combat, choose an opponent. They score 1 point,"* triggers.

### Why this counts as a combat death
* **Presence and Designation:** A unit is "in combat" as long as it holds an **Attacker** or **Defender** designation. These designations are assigned when a unit enters a contested battlefield and are only removed during the **Combat Cleanup** step (Rule 323.2) or when the combat ends (Rule 461.7.a).
* **Timing:** Because the Deathknell trigger resolves during the combat phase (before combat cleanup), Draven is still present and designated as an Attacker or Defender when he is killed. Therefore, his death trigger is satisfied.

### Important Nuance
If Draven were moved away from the battlefield (e.g., by a spell or effect) *before* the Deathknell effect resolved, he would lose his combat designation. In that scenario, he would no longer be "in combat," and his death trigger would not activate (FAQ #835). However, as long as he remains at the battlefield, the death counts as occurring in combat.

Note: I could not fully verify this ruling against the retrieved rules.