Requirement: Prestige Class Trainer. In Warj'Arune, you must unlock the 1st level of this prestige class by visiting a temple of whatever deity you wish to become a champion of, convert if you are not already a follower, and spending one or more nights in prayer and meditation. Whenever sufficient time has passed, the deity will begin granting you power (and access to this prestige class).
All Divine Champions must have an appropriate patron deity; after all, their power must come from someone. Inevitably, those deities that maintain a number of Divine Champions in their service are Good in alignment, though a Divine Champion may be either Good or Neutral themselves.
Note that Divine Champions may never be Knights of The Last Stand (i.e. have levels of the Paladin Class) and vice versa, as this doesn't fit into our storyline. Also, if a Divine Champion or Knight wishes to role-play a "fall-from-grace" story, and become a Blackguard, the player will need to seek out a DM and work it out with them. Likewise, a player with a Blackguard character who wishes to role-play a "redemption" story must seek out a DM as well, and go through an arduous set of quests.