When Flurry of Blades kills a unit during a resolving chain, does Immortal Phoenix's triggered ability immediately trigger and add itself to the resolving chain, or does it wait until the next Open State?

Question

Accepted Answer

Ruling: Immortal Phoenix's triggered ability triggers immediately and is added to the chain after Flurry of Blades resolves. It does not wait for the next Open State.

Sequence:
- Flurry of Blades resolves
- Phoenix triggered ability is put on chain
- Any player can react to it
- Phoenix triggered ability starts resolving
- You can pay {1}{F}
- If you paid, Phoenix itself is put on chain as pending item
- Phoenix triggered ability ends resolving
- Phoenix itself starts finalizing
- Make all necessary choices (where to put it)
- Phoenix finalized and resolves immediately (put at chosen location)

Nuances:
- All main deck cards and abilities start as pending items on the chain
- The pending items concept delays making necessary choices and paying costs during resolution of another item
- In most cases the pending concept doesn't need to be explicitly considered, though all chain items technically start as pending