In Riftbound, can you change the targets of Falling Star after the first 3 damage is dealt (e.g., after opponent plays Discipline)?

Ruling: You cannot change targets after they are chosen. Both targets must be chosen at effectively the same time when Falling Star resolves, and cannot be changed later even though there are windows to react between damage instances.

Sequence:

1. Falling Star is played (opponents can react here before targets are chosen)
2. Falling Star resolves and both targets are chosen simultaneously
3. Two damage effects are created and go on the chain (opponents can react here before any damage)
4. First 3 damage resolves (opponents can react here)
5. Second 3 damage resolves

Nuances:

• There is a window to play Discipline (or other reactions) after Falling Star is played but before targets are chosen, allowing you to avoid targeting that unit - but this would be a bad play since the opponent can just wait until after targeting
• Reactions can occur at three different points, but targets are locked in at step 2
• If units are removed before targets are chosen (e.g., via Retreat), the caster must target remaining legal units, including their own if necessary