Does Darth Nihilus work under Vader (zeta) leadership?

So his unique pairs quite nicely with zader, as it's just that many more dots flying around. In terms of overall, I'm not sure yet, as I haven't tried him yet, but I can imagine all the dots everywhere do great to reduce his annihilate cooldown. Is his unique zeta a must-have? No. It does nicely if you're using him in combination with an Assassin-Savage combo, where he can help do a 1 shot on someone, but it's not something to write home about.