Secret Paladin relied incredibly heavily on Divine Favor...So I'm not sure it survives the rotation.
That said, if it does survive, this is great protection against AOE. You make your opponent's life really difficult with a combination of this, noble sacrifice, redemption, and auto-defense. It's hard to get a read on all of them.
It's rated paladin secret/10.
As far as paladin secrets go, it's pretty good. But paladin secrets are notoriously awful if not hard carried by broken cards like Mysterious Challenger or Divine Favor (or both).