Breloom Level 100
Ability: Technician or Poison Heal
Nature: Adamant or Jolly
Moves: Mach Punch, Bullet Seed,
False Swipe, Spore/StunSpore
Item: Leftovers or Toxic Orb
Note: Mach Punch and Bullet Seed have high PP and hit hard if you have Technician as ability. Spore is a 100% accurate sleep inducing move that will help you increase your catch rate but it wears off so Stun Spore is also a good option to induce paralysis which doesn't wear off. Poison Heal is an useful ability in conjuction with Toxic Orb that way Breloom is immune to status and heals by itself. Technician boosts the power of False Swipe so I prefer to use that ability. Bullet Seed can OHKO Sturdy pokemon like magnemite making it very useful
Bisharp Level 100
Ability: Inner Focus
Nature: Adamant or Jolly
Moves: Iron Head, Night Slash, False Swipe, Thunder Wave
Item: Leftovers
Note: Bisharp is another option with different STAB moves in case the pokemon you want resists Breloom's moves. It can be used as a secondary false swiper in case you run out of PP restoring moves or you get bored of using Breloom.
Smeargle Level 100
Ability: Technician
Nature: Adamant
Moves: Soak, False Swipe, Glare/Spore, Crunch/Shadow Claw
Item: Leftovers
Note: Smeargle can capture Ghost-types thanks to it being able to use Soak to remove the their immunity to Normal-type moves and False Swipe. A Dark/Ghost move is used to KO the Ghost you don't want to capture.
If you don't have a Smeargle and do not want to use a Status move Mega Pinsir can use a Flying-type False Swipe to hit Ghosts.