Gengar-I would suggest more reliable moves instead of solely depending on Hypnosis to work. Replace Dark Pulse for Substitute and Nightmare with Thunderbolt/Energy Ball
Mismagius- Psywave? Astonish?! Goodness gracious man! Your HUGEST mistake is using Mismagius for a defensive wall. Personally, I think you should go with Dusknoir who is a much better tank then sweeper-like Missy.
Drifblim-You've got a mixed set going on there and it's not doing you any wonders... Drifblim's stats are slightly better in the special category so I'd say try:
Chandelure- One of the newest and most frequently used Poke out there at the moment. Go with Flamethrower, Energy Ball, Calm Mind, and Shadow Ball. This guy is an EXCELLENT sweeper, assuming of course you put all his EV's into SpA and Speed.
Golurk-MAGNITUDE?! Girrrrrl... you need to teach him Earthquake. PRONTO. Magnitude is seriously very unpredictable and unreliable. I think the best option for this guy is the ol' SubPunch technique. Soooo:
Shadow Punch (for STAB)
Jellicent- This set is decent, except probably for Nightshade. If you're hellbent on beating your friend I'd say go with Will-O-Wisp instead. Or if you want, just teach him Scald for damage and a chance to burn him. Your choice.
Seeing as your team is mono-ghost, I think you should consider using Froslass on your team for a super effective hit on your dragon-loving bestie. Good luck in future battles!