[Nightwalkr]

Originally Posted by Fat Pocket

Seeing how Steel-types can be a bitch to this team, I would consider adding mons like Garchomp, Zapdos, or Gastrodon over Gardevoir's slot. Garchomp and Gastrodon can both utilize Ground STABs to remove Steel-types, while Zapdos has Heat Wave. Gastrodon provides you another Pokemon to check Rain, so you can be more flexible with your teammates, rather than always tacking on Abomasnow when facing Rain teams. Garchomp can be useful when facing Sand teams. Zapdos can provide this team with another Tailwind support (although you may want to utilize 3 atks instead).

I think I will stick with Life Orb on Infernape and go with Rock Gem on Rampardos. You should test it out, though, and see which item fits better.

Since you lack Rain now, I would consider dropping Thunder for Thunderbolt or Substitute on your Gengar. I also highly recommend going Timid on Gengar, cuz it's a frail mon that depends heavily on its Speed to finish off the opponent before they can attack.

Oh right, forgot to put that change on Gengar, although actually I think I'll change it to Energy Ball or Giga Drain. I'll be sure to do that, Thunder is way too unreliable outside of rain. Also, just to keep my options wide, would a Water Absorb Pokémon work OK too? It's not that I don't want to use the listed mons, I just want to look through everything I could have.

Originally Posted by Fat Everstone

If you wish to keep Gengar I'd remove Focus Blast due to its unreliability, and use Destiny Bond instead to KO something that is giving you a hard time. Timid nature would be nice as you can speed tie Latios at worst and Ghost Gem Shadow Ball can still OHKO it I believe. Maybe Substitute over Protect as it can allow you to dodge Thunder Waves/Spores. If you don't plan on leading with it much I'd stick with Protect.

I'd also think back to your matches. Have you used or did you find yourself needing an electric move quite often? Keep in mind STAB Shadow Ball and Thunder have the same BP on Gengar. I might be biased but I haven't really found myself in that scenario much, as such I'd probably go with something else, like Energy Ball/Giga Drain or even Confuse Ray.

For the last slot I suggest a Water type that maybe has Blizzard to abuse hail? There's a lot of good ones so I can't really make a definite suggestion.

Focus Blast did cost me some trouble first match (Missed Scrafty) so I can see what you mean. Thunder hit some common things (Suicune, Drizzletoad, occasional Zapdos for decent damage) but overall I can see what you mean that Energy Ball/Giga Drain would provide better coverage. And as for water type that can abuse Blizzard, do they really need STAB Blizzard or would it be passable if they didn't get STAB on it?

Edits

Nightwalkr / Gengar ♂
Item: Ghost Gem Ability: Levitate Nature: Timid
EVs: 4 HP / 252 Sp.A / 252 Spe
Moves:
~Shadow Ball
~Energy Ball
~Destiny Bond
~Protect

I'm also wondering about Perish Song. I've seen some Drizzletoads have it, would it be worth trying out or would it be mostly useless? And how does the speed tie with Latios work exactly, like how does it determine who moves first?