Play only during [DS's] turn.
Action: Each player must sacrifice a unit, if able.
Reaction: After a card is sacrificed, deal 1 damage to a target enemy unit or objective.
How does the timing of this combo go? Are both cards sacrificed before the executor reacts and puts out two damage? Or is it one sacrifice, one react, second sacrifice, second react? Does DS get to decide who sacrifices their unit first, or is it done simultaneously, or is there a rule/ruling that says who sacrifices first?