Talk:Mashu Kyrielight/@comment-30319914-20170517080031/@comment-28048698-20170517081550

The short explanation: It's when a Heroic Spirit possess a human's body. It isn't just a simple "possession" because there is a union between the human's soul and the Heroic Spirit's soul. That happen with Mashu Kyrielight and Gallahed, Rin Tohsaka and Ishtar, and with Waver Velvet and Zhuge Liang.