A bishop is the second class change version of a human Cleric. They have all the Major Heals, all Greater Heals, and all regular Heals. They are the only class to have Mass Resurrection, Greater Battle Heal, Salvation, Benediction, Restore Life, Balance Life, Body of Avatar, and the highest Resurrection exp % return.
With the Gracia Epilogue update, the system of Skill Transfer was introduced. So now when a bishop completes his Third Class Change quest, he receives 1 x Holy Pomander - Cardinal, which he can use to obtain one skill from either an Elven Elder or a Shillien Elder.