Howdy Guys and Girls :)
Since there is a lot of interest in the Fallen and Cypher - here's a little overview for their rules within the book.
While Guilliman and Voldus can be taken by any Armies of the Imperium, regardless of their faction, you have to follow the rules for fielding Fallen Angels. They are their own faction and have allies restrictions, aswell as their own Secondary Objectives. Sadly no Terminators, Dreads or other stuff - but you have allies for that :)