Originally Posted by
Talanic
Getting raised is normal. But explicitly, this character is not getting brought back. That's really the one bit that makes this otherwise mediocre class special.
Dragged out my BOED for this. Character must have suffered martyrdom and not have been returned to life. "As a special feature of this prestige class, the character rises with the abilities of a 0-level Risen Martyr added to the character's previous abilities. When the character earns enough experience points to advance another level, he must become a 1-st level risen martyr."
In other words, the first level you take is level 1. You gain the abilities (Spiritual Body and +2 Will save) at level 0 for 'free' when you rise, but it's not a level. You don't gain hit dice or the .5 BAB; it's only a placeholder that locks you in to ten levels of Risen Martyr. Otherwise, it would be level 1 of Risen Martyr; why would they write it as level 0 if this is not what they wanted to indicate?
So yeah. Considering that the character was not getting raised by any other means, level 0 of Risen Martyr is a big jump in power - but only because it's compared with being dead.