Also is anyone disappointed that those girls with the pink and blonde hair didnt have much of a plot they were just in that house with old plasma
Rood isn't back with Ghetsis, he just battles you to see your strength. He's the one who gives you Zorua. I would say that Rood was released for cooperation, and Zinzolin was busted out by Ghetsis after Ghetsis promised power and authority to Zinzolin. Rood probably wanted nothing to do with it, and chose to wait for N to return.