If Divine Judgment is activated and the opponent responds by using Retreat to return one of their two units to hand, does Divine Judgment have no effect when it resolves since there aren't two opponent units to choose anymore?

Ruling: Divine Judgment does not specify that the two units must be controlled by your opponent. If there aren't enough units controlled by the opponent to choose, they must choose your units to fulfill the requirement.

Nuances:

• The card text "choose two units" does not restrict the choice to opponent-controlled units only
• If the opponent has fewer than two units when Divine Judgment resolves, your units can be chosen to meet the requirement