Knights of the Sun

Membership in the Knights is an honor that can be awarded on any member of the Church, as recognition of exemplary service in the fight against evil. Members retain their affiliation with their old order, but change their emblem to have a white sun, and are eligible to receive special training as a Consecrated Harrier, Divine Crusader, or Holy Archer, as appropriate.

Their training camp is in Maxaen.

Holy Archer

Raining down holy fire on the enemies of the Church, the Holy Archers are some of the most devastating ranged combatants in Crescent.

As Arcane Archer, except substitute all arcane-related abilities and requirements for the equivalent divine abilities.
All of the Holy Orders may freely multi-class with this Prestige Class, provided they meet the entrance requirements.
The race requirement is waived for this class.
Holy Archers are one wing of the Order of the Knights of the Sun.
Source: Dungeon Master’s Guide or SRD [1]

Consecrated Harrier

Enemies of the Church have no greater foe than the Consecrated Harriers, who are trained to track them down at all costs.

The requirement of having 5 Ranks Profession (Lawyer) is replaced with 5 Ranks in Knowledge (Religion).
Knowledge (Religion) is a class skill.
The Alignment restriction is waived.
The second level granted power of Detect Chaos is changed to Detect Evil.
All of the Holy Orders may freely multi-class with this Prestige Class, provided they meet the entrance requirements.
Consecrated Harriers are one wing of the Order of the Knights of the Sun.
Source: Complete Divine

Divine Crusader

Shock troops in the fight against evil, the Crusaders bring awesome melee capabilities to the fight for righteousness.

Note that ORB is Neutral Good in alignment; this affects who can join.
This prestige class is usually best for fighters who don’t have the dedication to law and honor required to join the Order of the Sword.
All of the Holy Orders may freely multi-class with this Prestige Class, provided they meet the entrance requirements.
Divine Crusaders are the final wing of the Order of the Knights of the Sun.
Source: Complete Divine.