A Worm's Fate

A foreign distorted soul finds itself inserted into the body of one Shinji Matou. It had no purpose, merely curious upon the odd yet familiar feeling of having a body until Matou Zouken had commanded it through the geass carved onto the body's being, "Protect Sakura from harm." (M because Matou. OC-Insert into Shinji Matou. Slight AU)