Speaking of which, I should give you a general idea of what a team actually needs. The general concensus of a balanced team suggests you have at least the following:
1 special sweeper
1 physical sweeper
1 special wall
1 physical wall
1 Rapid Spin user
A way to deal with Sleep move users, either by Insomnia, Natural Cure, Aromatherapy or Heal Bell, or by using Sleep Talk on a Pokemon and absorb the sleep move for your team.
A first strike move like Fake Out, Quck Attack, to deal with low health things which normally outspeed you
Some Pokemon can fill multiple roles, for example Forretress can be both a physical wall and a Rapid Spin user. Bronzong can take the role of a tank, which is effectively a wall for both physical and special moves. While we are here, let's define what the roles are:
Physical Sweeper: Anything with a high Attack stat, or a way to boost it's Attack stat and attack with massive damage, and often coupled with high Speed to get highly damaging physical moves at your foes. Weavile is an example of a physical sweeper.
Special Sweeper: Anything with a high Special Attack stat, or a way to boost it's SpAtt and attack with massive damage, and often coupled with a high Speed ot get highly damaging special moves at your foes. Alakazam is an example of a special sweeper.
Mixed Sweeper: Something with the capability of doing heavy damage with both physical and special moves. Infernape is an example of a mixed sweeper.
Physical Wall: Anything capable of taking physical hits for your team, in order to give your team some survival or force a switch. Often walls have a health recovery move to give them lasting power. Skarmory is an example of a physical wall.
Special Wall: Anything capable of taking special hits for your team, in order to give your team some survival or force a switch. Often walls have a health recovery move to give them lasting power. Blissey is an example of a special wall.
Tank: Something able to absorb hits from both physical and special hits. Bronzong is an example of a tank.
Cleric: Something with the ability to support the team with healing and recovery moves, more specifically Wish, Heal Bell and Aromatherapy. Blissey is an example of a Cleric.
Those are the general roles a team member can play. As for the case of Rapid Spin, a common selection of moves are Spikes, Stealth Rock and Toxic Spikes, which can do serious damage over time (especially if you are forced to switch). The use of Rapid Spin can be negated if you have a way of dealing with these moves. Steels and Poison types can come in on Toxic Spikes, Flying types and those with Levitate can ignore Spikes. Steelix for example has a 4 x resistance to Rock which significantly reduces the damage done from Stealth Rock. By keeping these three moves in your mind, you may not need Rapid Spin if you balance your team right, but it's much easier to get rid of them so you can get certain things in. Ninjask for example has a 4 x weakness to Rock, so in order to get him in safely you need a Rapid Spinner to eliminate Stealth Rock, otherwise he loses half his health just by switching in.
