Divine Deflection

Whether the targeted permanent or player is still a legal target is not checked after Divine Deflection resolves. For example, if a creature targeted by Divine Deflection gains shroud after Divine Deflection resolves, Divine Deflection can still deal damage to that creature.

If Divine Deflection prevents damage, excess damage (if any) dealt by that source is dealt at the same time. Immediately afterward, as part of that same prevention effect, Divine Deflection deals its damage. This happens before state-based actions are checked, and before the spell or ability that caused damage to be dealt resumes its resolution.

If Divine Deflection can’t deal damage to the targeted permanent or player (because the creature is no longer on the battlefield, or is no longer a creature, or the player is no longer in the game, for example), it will still prevent damage. It just won’t deal any damage itself.