Any tips on a full Kanto ONLY team?

Hello.

So me and a few other friends are playing "together" on different devices and are going to have a competitive turnament using ONLY things that can be obtained throughout the FireRed and LeafGreen titels, with the only exeption being that we can use megastones. Any ideas for a team around Nidoking? Or is Nidoking not a viable pokemon?

PS. I almost know nothin' about competitive stuff, so any help is appreciated!

Thanks

Well, items are a stretch. The best competitive items you can get purely in FR/LG are the Sitrus Berry, Lum Berry, Quick Claw and the Leftovers, although all are very good nonetheless. Mega Stones will certainly buff your team but if I'm correct, duplicate items aren't allowed.
The Lax Incence will reduce enemy accuracy, but it's not entirely reliable. Since you can't get the Choice Band without a Hoenn game, the King's Rock is a good option for that last slot, as are the Figy, Wiki, Mago, Iapapa and Aguav berries if you know your Pokemon's Nature and are bringing the Pokemon to Alola. Alternatively Nidoking could run Thrash or Rest and use a Persim or Chesto Berry to recover from the ensuing condition, respectively.
I also just realized that most of FR/LG's best items are berries...
If you plan on using that Nidoking, I'd use a team that can cover its weaknesses to Water, Psychic and Ground moves, which would mean at least one Grass-type Pokemon could be handy. You could also use a Bug-type to counter the psychics. Although I wouldn't reccomend Parasect for either of these roles, as any Flying or Fire attack will destroy it in one hit.

First of thanks for taking your time to answer.
Secondly the thing that I'm more so wondering about what pokemon to use and for what reason. I did some research and found out that a team should consist of:
Physical Sweeper (Pokémon with high Attack stat)
Special Sweeper (Pokémon with high Special Attack stat)
Physical Wall (Pokémon with high Defense, who can soak up damage)
Special Wall (Same as Physical Wall, but for Special Defense)
Lead (Pokémon who sets up entry hazards or field conditions early in the game.)
Crippler (Pokémon who inflicts status conditions, then switches out to a Sweeper)
(from WikiHow)

Any idea of what pokemon to use for each role? Do you also know about any good kanto cores that has good synergy (could maybe try and make a good team myself around the core)

Thanks once again for the answer and potential new answers. Appreciate it very much.

Thanks for reminding me that this is a team-based thread. Anyway there aren't any Kantonian spike-setters from FR/LG, save Cloyster, so that's a nice lead. Alternatively you can venture into the post-game and capture Qwilfish or Skarmory in Fire Red; Skarmory is, knowledgably, the better option and can be caught at Sevault Canyon. Even then, the only trap move in this generation is Spikes.
Since you wanted a Kanto only team, though, Cloyster is the best trapper, unless you breed Spikes onto an Omanyte. Even then, it's probably better to use Cloyster, but good old Lord Helix has a few tricks of his own. Essentially, even with Omastar involved, Cloyster is the best option. if you plan with Spikes.
The rest of the team I'm still working on, but that Nidoking could serve as a good physical sweeper or tank, depending on how you build its stats.

So if I use cloyster as a lead and teach him Spikes, is his only purpose then to start the battle by placing down spikes (By the way, is it worth the turns to pull out a triple spike?) and then just die? Or should I have a pokemon (like a wall Nidoking) to switch out to incase of checks? What I'm trying to say is that I don't know if Cloyster is worth having as a sweeper also or a Physical wall, bc of 180 base stat defence. Let me know about that one and also thank you so very much for the effort your putting in to help me. (I know I've said that multiple times now, but I really do appreciate it)

By the way, we made a new rule that we can use all kinds of items up to i think XY or ORAS, so Life Orb and such is avalible.

So full Item circulation? That could fix a few problems. However I'm not entirely into competitive, so Cloyster's role is still kind of an unknown for me. Usually I give it some attacking moves and Spikes, it is a Pokemon that I never really focused on though so you're on your own for most of the team. Sorry, but at least we found a Spikes-user.