Level 11 DiseaseSoul Rot

Stage 0: The target recovers from the disease.
Stage 1: Initial Effect: The target takes 5 necrotic damage and loses one healing surge that the target cannot regain until cured of the disease.
Stage 2: The target is weakened until cured.
Stage 3: Final State: The target dies and rises as a wraith.
Check: At the end of each extended rest, the target makes an Endurance check if it is at stage 1 or 2.
15 or lower: The stage of the disease increases by one.
16-20: No Change
21 or higher: The stage of the disease decreases by one.

Published in Manual of the Planes, page(s) 52.