you need two different Pokemon an electric type 50 plus level , to beat gyarados.. and to beat the dragonair and dragonite you need ice beam or blizzard. To beat aerodactyl surf. I find 50 level lampras or blastoise works best
lance
you have to defeat the gym leader in the 5th gym or something ...
I get the strongest Pokemon I can get without them disobeying me then I battle the gym leader. I usually focus one or two Pokemon that could defeat the gym leader alone and I train them until I think that they are good enough to defeat the gym leader.
First, you have to either defeat or capture the Red Gyrados in the Lake of Rage. Follow lance to a building with a funky looking tree with an antenna sticking out of the top of it. Lance will open up the secret Team Rocket layer, where you have to defeat its leader, and then the Mahogany Town gym will open for you to defeat Pryce.
You defeat the trainers and the gym leader, Misty. Electric attacks are best for this gym.
You go on to defeat the eight gym leader.
you have to get the legendary in the game
well you will have to defeat the 5th gym leader and once you defeated her she will give you the TM move shadow claw you will find the 5th gym leader at hearthome city before you deafeat the gym leader you will need to defeat the 4th gym leader in order to defeat the 5th gym leader
Defeat the Cianwood city gym leader, then talk to a lady outside the gym and talk to her. She'll give you HM02 (Fly) and if you try asking BEFORE you beat the gym leader she'll not give it to you then, but once you defeat the gym leader.
The gym leader you must defeat is Morty, the ghost-type gym leader who lives in Ecruteak. To defeat him, try using types such as ghost, dark, or psychic.
It depends on what gym leader you are one. If you are in Violet City, you must defeat the first gym leader and travel to Azalea town to defeat the rocket grunts in the slowpoke well. Usually, just defeating the gym leader of your current city is all you need to do.
In which Pokemon game?