Vaa-tumor

The Vaa-tumor was an affliction specific to Yuuzhan Vong master Shapers, and was believed to have been a piece of brain matter of the goddess Yun-Ne'Shel herself. Each Master had to go through a period of personal sacrifice, during which a piece of the tumor was implanted in their body. The pain had to be endured, as the tumor supposedly altered the Shaper's own cells and brought her closer to Yun-Ne'Shel. After the period of sacrifice, the tumor was removed, and the Shaper was changed forever.