Pokémon FireRed and LeafGreen/Seven Island

Seven Island is the last of the Sevii Islands. There are two places to visit: the Trainer Tower and the Tanoby Ruins.

Pokémon found

 * (LeafGreen)
 * (FireRed)
 * (FireRed)
 * (LeafGreen)
 * (LeafGreen)
 * (FireRed)
 * (FireRed)
 * (LeafGreen)
 * (FireRed)
 * (FireRed)
 * (LeafGreen)
 * (FireRed)
 * (FireRed)
 * (LeafGreen)
 * (FireRed)
 * (LeafGreen)

Trainer Tower
On the island, go north to the Trainer Tower. Here, you must go through eight levels of trainers to reach the top and claim your prize. Battling the trainers here will neither give you levels nor money. These battles are timed, so try to do your best. The level of the Pokémon here will match the level of your highest level Pokémon. There are 4 modes: Normal, Double, Knockout, and Mixed.

Normal are just single trainer battles. Beat 8 trainers and be rewarded with an Upgrade (to evolve Porygon into Porygon2 through trade).

Doubles are double battles. Beat 8 couples and be rewarded with a Dragon Scale (to evolve Seadra into Kingdra through trade).

Knockout means one after the other with no healing time. Beat 8 levels containing 3 Pokemon each and be rewarded with a Metal Coat (to evolve Onix and Scyther into Steelix and Scizor by trade respectively. Also powers Steel type moves).

Mixed is a combination of all of the above. Beat 8 levels and be rewarded with a King's Rock (to evolve Polywhiril and Slowpoke into Politoed and Slowking by trade respectively. Also adds a chance to make the opponent flinch when attacked).

Tanoby Ruins
Following the road south you'll find the strongest common trainers in the game, so it's a great place to train. There are a couple of useful items that you can find throughout the road (King's Rock requires Strength and Rock Break). In addition, the grass contains new Pokemon, Phanpy and Larvitar, which can evolve into powerhouses! In the middle of the road you'll find a cave with a simple puzzle to solve. Push all the boulders into place and an earthquake will take place.

Head further south and enter the Tanoby Ruins. Solving the earlier puzzle allows you to capture Unown within these ruins! I know, a crappy reward for all the struggles you went through, but at least, you have finished exploring the Sevii Islands! Head back to Victory Road. The Elite Four are ready for a rematch and are waiting for you!