Double Payback

"Double-Back" can be activated when you take 1000 or more damage from an opponent's card effect. (It cannot be activated during the Damage Step.)

The effect "Place 1 Double-Back Counter on this card for every 1000 damage you took at that time" is the effect resolution that occurs when the activation of "Double-Back" resolves. (This effect does not target.)

The effect "During the next opponent's End Phase, destroy this card, and if you do, inflict 2000 damage to your opponent for each Double-Back Counter that was on this card" is an effect that creates a Chain Link. (This effect does not target.)

The process of "destroy this card" and the process of "inflict 2000 damage to your opponent for each Double-Back Counter that was on this card" are treated as occurring simultaneously.