What does assassins creed have to do with the world ending?

I am going to say this first

*SPOILER* *SPOILER*

When you find the Vault you find all the Roman gods, Minerva speaks to you and tells a story on how long ago the Sun burnt the Earth, and its going to happen again in Desmond's time, the only way to survive is to find sacred temples, and on the way stop the Templars from acquiring the Apple of Eden