Each generation has its own fifth gym specializing in its own kind of Pokémon. Because of this each generation has a different strategy to defeating the leader and his trainers more easily.
Generation I's fifth gym is Fuschia Gym, which specializes in Poison-Type Pokémon. Poison-Types are weak to Psychic-Types and Ground-Types, though as many of them are part Grass- or Bug-Type, Fire-Types would also work well.
Generation II's fifth gym is Cianwood Gym, which specializes in Fighting-Type Pokémon. Fighting-Types are weak to Psychic-Types and Flying-Types.
Generation III's fifth gym is Petalburg Gym, which specializes in Normal-Type Pokémon. Normal-Types are weak to Fighting-Types, but it would be more prudent to prioritize Speed, Defense, and strategy over Attack.
Generation IV has two fifth gyms; in Diamond and Pearl, it is the Hearthome Gym, which specializes in Ghost-Type Pokémon. Ghost-Types are weak to Dark-Types and other Ghost-Types, though Electric-Types would fare well against Drifloon and Drifblim, and a strong enough Psychic-Type would be useful against most of the other Ghost-Types (members of the Gengar family, which are part Poison-Type). In Platinum, however, it is the Pastoria Gym, which specializes in Water-Type Pokémon. Water-Types are weak to Electric-Types and Grass-Types, and due to the fact that he has a Quagsire (which, due to its Ground-Type status, is immune to Electric-Types), it is recommended to have at least one of each.
Generation V's fifth gym is Driftveil Gym, which specializes in Ground-Type Pokémon. Ground-Types are weak to Grass-Types, Fighting-Types, Water-Types, and Ice-Types.
Generation VI's fifth gym is Lumiose Gym, which specializes in Electric-Type Pokémon. Electric-Types are weak only to Ground-Types.
To beat Norman the 5th gym leader you must have a blazeakin level40-50 and make sure it nows double kick.after you get that,go to the gym and go through all rooms then when you beat everyone go to Norman and battle. Keep using DOUBLE KICK.
EDIT:
To beat him, you don't need a Blazeakin. you can also use a Hariyama and train it to level 30 and a Sableye and train it as well. If you use a ghost type, most of the moves can't touch you because normal has no effect against ghost. Otherwise if you didn't get the fire/fighting type in the beginning, you can still beat him.
To get Hariyama and Sableye, you can just go to dewford and hike around in the cave you met Stephen in. Capture them and just train them up in the desert.
Good luck!
EDIT: ^above^ You cannot catch a Hariyama in that cave, they evolve from Makuhita which is what you will find in that cave, most of the Pokemon found in the cave are levels 6-9, the Makuhita evolves at level 24.
its all about power. Dont worry about his poliwrath because electric takes it out. But primeape its kind of tricky. You cant use flying type because he kills them with rock slide. If you caught that suddowoodo then he has the move faint attack which can never miss so when he uses focus punch use faint attack but he will keep using it. Then get his health down as much as you can then use flying and it should be able to kill him
With a dark type Pokemon
like murcrow
hes the fifth gym leader
You need to defeat the gym leader before you can get it. After you beat Maylene (The Gym Leader) and heal at the Pokemon Center (This is optional but I suggest you do). After you heal at the Pokemon Center, go to the Galactic Warehouse. (You will see it when you get to Veilstone City). Team up with Dawn or Lucas to beat the Galactic Grunts, and go in the warehouse and pick up HM02!
First battle Chuck, the gym leader in Cainwood City. If you win, when you get out of the gym, his mum will give you HM 2, Fly.
Beat the GYM LEADER [=
8th gym leader
it is the grass type gym leader, gardenia. She is the second gym leader. Oh and you also get your bicycle there AFTER you beat the gym leader, and the team galactic comander, Jupiter. . . your welcome ^ ^ O
You get Fly after you beat the 5th Gym Leader (Chuck). Chuck's wife will be outside the Gym, and if you talk to her, you will get Fly.
go to olivine city and beat jasmine the gym leader. after, got to mahogony town and defeat the gym leader pryce. lastly, go to blackthorn city ond beat their gym leader, clair.
You beat Chuck, the 4th gym leader, in Cianwood city. After you beat him, leave the gym. His wife will come up to you and give the HM to you.
Beat the Cianwood Gym leader, Chuck. Then a woman will apper when you leave the gym and give you the HM.
You probably skipped the sixth Gym Leader, Jasmine. Common mistake. You beat Chuck, get Fly, and surf to fight Pryce. But, you forget to fight Jasmine...
fighting types, the gym leader is chuck
After you beat Chuck, leader of the Cianwood City gym, talk to his wife who is walking in front of the gym. She'll give it to you.
After you beat Leader Chuck at the Cianwood Gym, step outside and his wife will give you the HM Fly
in jhoto, you have to beat chuck (the 5th gym leader) and then talk to the person outside the gym (a girl). chuck will give you the ability to use fly out of battle and the person will give you the HM.
The Sixth Gym leader is Chuck, he has a Hiryama and a Poliwrath.
First, defeat Chuck, the 5th gym leader. Then go outside and talk to his wife. She will give you fly.You get it when you beat the flying type gym
wat u hav to do is beat the gym leader to get the badge noob. The 6th can be Jasmine, Chuck or Pryce. To beat Chuck get to Cianwood and raise the waterfall with a switch at the back of the gym. To beat Jasmine you must take the medicine to her and the Ampharos at the top of the light house. To beat Pryce you must first meet Lance at the Lake of Rage.