You can choose one or the other. Your typing ability inhibits me from understanding what you are trying to convey...
I'll just think about it the way I think you tried to putreydufgdsdg whatever.
No you don't need Factions to run Nightfall. You don't need any of the other games to run one. They're like expansion packs, but can be played as stand alone games.
Trilogy comes with all 3 games, so idk. It comes with Nightfall. Wat.
If you're playing GW, gimme your name.