Definetley Gengar because Staraptors moves would not effect Gengar as he is ghost type. Gengar also learns better moves like shadow punch at leval 25 and destiny bond at level 39. Just so you know in case you did not destiny bond if used curses the other Pokemon so if your Pokemon faints the other one does to. Hope I helped :)
staraptor, no question
electrive because venasaur and gengar are part poison, and electrive has better moveset.
Staraptor is a Normal and Flying type pokemon.
you have to trade a haunter and it will evolve into gengar.
ditto or another staraptor make sure they are opposite gender.
Ryperior Tyranitar infernape staraptor lapras Gengar
I think Lucario.
Choose Infernape , Empoleon , Torterra , Glaceon , Honchcrow and Garchomp
it depends on levels
staraptor, no question
Gengar! I have a lvl 100 Gengar! He's AWESOME!
roserade rapidash empoleon gengar luxray staraptor for e4 all lvl 65
my opinyon the stater staraptor garchmp giratina gengar rapidash and togikiss
if high lvl and good moves the they should be fantastic
I think that's a pretty good team,as long as they are all at good levels.
Gengar, Staraptor and infernape are some pretty good pokemon you should try those, I know they are some of my favourites.
A good team for Pokemon diamond or pearl is probably Empoleon, Staraptor, Roserade or, Steelix, Machamp, and Haunter or Gengar.