Aggro Paladin is a relatively old archetype in Hearthstone which allows Paladin to take advantage of cheap minions and the powerful and aggressive class card Divine Favor. In Standard, it relied on strong class cards like Shielded Minibot and Muster for Battle.
Kobolds and Catacombs has given this deck a lot of power with the class card Call to Arms that can instantly create a board. Val'anyr, which is Paladin’s new Legendary Weapon. And finally one of the strongest cards in the set, Corridor Creeper.