Divine Retribution is, in a way, another version of Blinding Flare, making it harder for the opponent to attack you, especially with units with low life.  Unlike Blinding Flare, it is a lot cheaper and a lot easier to set up. While playing this card just in a vacuum is not very valuable, it’s never terrible either. This becomes a massive event when you have Spirit of the Phoenix also active. Other good uses are when the opponent has a 1 life unit to attack you or your opponent has units that can attack twice. Even when the opponent’s units have 2 life, Divine Retribution is still pretty good, as it can make the units have only 1 life left the next turn, when you can then easily clean up with Ember Archers and Ember Beast's Wildfire.