Villengard won. It’s a bootstrap paradox

Villengard’s goal was to inspire the very religion that would eventually evolve into the Church, because as seen in Boom, the Church is Villengard’s number one customer. The whole thing is a capitalistic bootstrap paradox.

The Doctor assumed that Villengard’s plan involved blowing up the planet, but Villengard’s plan actually worked perfectly. The star seed bloomed and the flesh rose. The Doctor said the case emits a psychic field which possesses people, and that’s exactly what happened to Joy. She killed herself to explode into a star and convinced herself it’s what she wanted. That’s religious extremism.