Twin Cross

A priest and a young warrior with mysterious pasts happen to cross paths when they save a seer-in-training from an attacking monster during their separate journeys to visit the oracle. Each seeks advice to help find someone very important, but once they reach the oracle's residence, trouble meets them there as well. Thus begins a fantastic tale that involves humans, dragons, phoenixes, and an ancient kingdom caught in the middle of an attempted revolution.
Note: Volume 1 contains a one-shot titled "Seiju no Kajitsu" about a young witch who seeks the legendary "fruit of the holy tree" in order to save her fiance's life.
Another Note: The series ends at volume 4, but volume 5 contains 2 side stories related to the main characters.