Who gets focus if there are multiple open states during the same combat, and can you insert new reactions in the middle of a chain as stuff resolves one by one?

Ruling: Focus goes to the player who didn't start the previous chain. You can insert new reactions in the middle of a chain as stuff resolves one by one.

Sequence:

• Combat starts with the attacker having focus
• After the chain clears, focus goes to the defender
• After that chain resolves, focus goes to the player who didn't start the previous chain