Let me present to you the best catching Pokémon you could ever have.
That's right, it's Bisharp. Now let me tell you exactly how amazing this thing is.
First of all, there's its typing. Steel resists a heck of a lot of types; no need to explain that. Dark is also pretty good, especially for catching Mewtwo or something similar.
Second, there's its ability. Defiant provides a nice boost to Bisharp's Attack when its stats are lowered, especially since False Swipe is a base 40 power move.
Third, it's capable of learning the moveset to become an amazing catcher.
Here's the set you should use:
False Swipe - Here's an obvious one. No need to gamble with other moves when you can reliably get the opponent down to 1 HP with this.
Thunder Wave - Even though it doesn't give quite as much of a boost as sleep when trying to catch a Pokémon, I prefer paralysis because it's permanent.
Taunt - If it's paralyzed and down to 1 HP, the only thing that can stop a Pokémon from being easy to catch is if it uses Recover or Roar (or any moves similar to these). Fortunately, Taunt easily solves this problem.
Night Slash - If you're trying to catch a Pokémon, there's a good chance you could accidentally start a trainer battle and/or will try to catch a Pokémon in a horde. False Swipe may be a good move for attacking, but it sucks when trying to KO anything. I chose Night Slash since it's a nice STAB.
You can use Bisharp to catch pretty much anything, but it has three main weaknesses: Ghost, Electric, and Ground types. This is because they can't be affected by False Swipe and Thunder Wave respectively. If you want a reliable backup, I'd suggest Smeargle.
Item: Leftovers (if you want)
Ability: Technician (works well with False Swipe)
- Foresight (letting Normal moves hit Ghosts)
- False Swipe (obvious)
- Glare (paralysis)
- Spore (sleep)