I might be too late to reply to this since it was posted three days ago... but never mind.
You biggest flaw is without a doubt your lack of dragon and ice type moves. You'll have to SERIOUSLY outlevel Lance if you want to take him down without supereffective moves. Especially if your pokemon is not EV-trained, and many of the elite four pokemon will be faster. I rarely bother to EV-train much for the story run, but you might want to at least consider the natures of your pokemon, since many of them might still be under-leveled. As already pointed out, you'll want to evolve both your Nidorino, and your Poliwhirl. There are also no real support moves. They can be very useful, if used correctly.
Overwhelmingly, I feel like you would benefit from reading up on the type-machup chart: [link]
A well-rounded team will have a few moves that will hit hard on the most common types. Since the pokemon used by the Elite 4 are known and can be looked up, creating a team specifically made for beating them should be a possible feat.
Yep, that chart is extremely useful and I'll keep referring to it all throughout the prep process. I think I'll go with ice-type moves - as DomnuWyrda advised me yesterday, Nidoking might do the trick with an Expert Belt/Nevermeltice and Ice Beam? I've evolved Nidorino into Nidoking already, now I just need a Water Stone to evolve Poliwhirl into a Poliwrath. However, I haven't really done much EV training but I guess I can use a few Vitamins to boost weaker stats beforehand.
If you don't mind me asking, should I stick to Poliwhirl>Poliwrath or change to a Gyarados, considering more dragon/ice type moves would be possible that way?
Don't randomly boost stats with vitamins. A pokemon will be at its best when specialized, and you will still have to level them up a lot if you want to reap the benefits. Pick speed and attack stats that are compatible with the already existing stats/purpose of the pokemon.
As for the water type... well, you could go either way. Gyarados is generally a better pokemon, but require a bit more specialization due to its x4 weakness to electricity. That's going to cripple you against lance, if you cannot outspeed and (1HK) his Dragonites, who know thunder/bolt.
Poliwrath have no real distinction in its attack stats and hit weaker, but will be able to provide for some much needed fighting moves (I suggest getting rid of Double kick on nidoking, since it's a pretty pathetic attack compared to what's actually available for it). It also packs a bulk and have really useful resistances. It probably comes down more to preference in this case.
You could go with poliwrath and teach it ice punch through the move tutor(I *think* you can do that, but look it up...) and give Nidoking the ice beam TM.
Thank you for telling me that, I'd be pretty stuffed if I went in and just fed vitamins :\ I'll definitely do a lot of level grinding.
In that case I'll stick with Poliwhirl > Poliwrath. I'm going to go with Sludge Bomb, Earth Power, Thunderbolt, Ice Beam for Nidoking. For Poliwrath- Waterfall, Brick Break, Hypnosis, Earthquake? I think that moveset would work. I'll look up the move tutor and collect a whole lot of Heart Scales. Thanks again!
It's a good generic movepool for Poliwrath, as it hits everything with neutral damage. However, it's got little to say against Lance. It's got literally NO moves that are super effective against ANY of his pokemon, leaving you to have to rely on nidoking to sweep his entire team. I would really reccomend getting an ice- or rock type, damage dealing move for Poliwrath. If you have it and want to use it on Poliwrath, rock slide can be an alternative for ice punch. Another idea could be to replace it with an ice-type all together, and evolve the Eevee into vaporeon. It will learn aurora beam by leveling up.
Ah, is it? I might go with rock slide then, because it's a bit of a bother having to replace it altogether. It's a possibility though, so thanks for telling me! I'll think about it. Thank you again for your help!
Goodness, your movepool is absolutely horrid. Take my advice here:
Typhlosion: Flamethrower, Lava Plume, Sunny Day, Solarbeam Ampharos: Charge, Discharge/Thunderbolt, Signal Beam, Something with a base power over 60 Poliwhirl -> Poliwrath: Waterfall, Brick Break, Hypnosis, Earthquake Poliwhirl -> Politoed: Surf, Ice Beam/Blizzard, Psychic, Hypnosis Noctowl: Air Slash, Uproar, Light Screen, Substitute/Reflect Nidorino -> Nidoking: Sludge Bomb, Earth Power, Thunderbolt, Ice Beam
Decide what your Eevee is going to be. Given that your team covers almost all of the types an Eeveelution would fill, I'd recommend Umbreon. At no point past the fourth badge should your Pokemon have any move with a base power less than 60 or 70. Also make sure to level grind to about 60 or so. That level 27 Eevee is just mocking me.
Yes you're right, that's why I decided to find help since I'm pretty much stuffed.
I've moved on a bit since the first post and I've evolved Nidorino to a Nidoking, I've yet to find a Water Stone to evolve Poliwhirl into a Poliwrath. I'll be sure to stick to your suggested moves. I'm guessing I can go to the Move Maniac in Blackthorn City to teach moves I may have missed out, or are those moves all TMs that I can teach? I'll definitely change to those moves though.
I've decided to evolve Eevee to either Espeon or Umbreon, now I'm just comparing the two and seeing which would be most effective and useful against the Elite Four. I'll remember that. Eevee is only level 27 because I didn't know what to evolve him to so I stopped levelling him. Thanks again for your advice, I'll definitely take your advice here.
I usually conserve my TMs until I absolutely need them for things like this. Earth Power may be the only move you'll have to remember, as the rest are TMs. If you haven't been using them up until now, you should be able to make the moveset changes without much ado trouble. The double screens on Noctowl will be a saving grace, and Ampharos learns all the moves I listed as he levels up. The TMs can either be bought or won in Goldenrod City.
Going with Umbreon, I'd recommend teaching him Payback. Umbreon isn't fast as a rule, being a wall, and the 100 base-power of a slow Umbreon's Payback makes up for the lack of offensive stats. (If you could breed it, Wish would be an excellent egg move to tack onto an Umbreon)
Espeon, while powerful, is a wee bit short on versatility. Expect Psychic, Shadow Ball, Grass Knot, and Hidden Power to be your only offensive options should you choose it. Though you might want to consider having that powerful Psychic for the E4's Bruno: He's loaded with rock-type moves that will cripple Flying-type Pokemon like your Noctowl.
Given your changes, Espeon seems like the better option IF you teach it Shadow Ball. Shadow Ball combined with Espeon's naturally high Special Attack will help you wreck your way through Will and Psychic will mutilate Koga and Bruno. The added perk of Espeon's Synchronize ability doesn't hurt either.
Will: Stick to Espeon, Typhlosion, and Ampharos Bruno: Batter his defenses with Espeon and Poliwrath Koga: Espeon, Typhlosion, and Noctowl will wreck him Lance: Any Ice-type moves you can place on your team? Without them, you'll get mowed down by Dragonite. Gyarados can get them with Ice Fang or Avalanche, but Nidoking might do the trick with an Expert Belt/Nevermeltice and Ice Beam. (Nidoking can also block out Dragonite's Thunder Wave, but be wary! I think one of them has Blizzard, which will completely destroy him.)