The second variety of pokemon to talk about are Sweepers.  Sweepers are pokemon that are fast, usually frail, and possessed of amazing offensive capability.  The entire point of a Sweeper is to take advantage of the speed element of the game to crush all opposition before it has a chance to strike back- even at the cost of recoil damage to the Sweeper.  Sweepers don’t bother with status effects- anything it does aside from damage is pretty thoroughly incidental.  Occasionally a sweeper will need to ‘charge up’ before sweeping, through Swords Dance, Dragon Dance, Nasty Plot, or some other boost- but the best sweepers come out running and smash holes through anything in their way.

Sweepers typically have mediocre or poor defenses and HP, relying on their impressive Speed and equally daunting Attack or Special Attack to break it before it can break them.  Sweepers with good defenses and defensive Abilities are rare, with the exception of abilities that protect from Paralysis or Burn type effects.  Many sweepers have Abilities that boost their sweeping, from the occasionally-useful Limber (ignores paralysis) to the abusable Guts (Boosted attack power when Burned, Poisoned, or Paralyzed) to the horrifying Moxie (Attack stat raises every time it knocks something out) and Defiant (Attack stat gets a large boost every time any stat is reduced).  Sweepers will usually have access to a variety of moves, but have a considerable array of high-power attack moves, often carrying recoil or other drawbacks like a loss of defense.

Some of the nastier sweepers include Alakazam, Gengar, Infernape, Volcarona, Jolteon, Staraptor, and sometimes Blaziken.

Sweepers are great pokemon to have on your team.  Speed is always important if your goal is to knock out opposing pokemon and boy howdy do these pokemon do that.  With high power, they can cut through anything but a wall- and walls aren’t going to be doing much damage anyway, are they?  Especially when high powered moves meet high offensive stats, spiralling the offensive strength all that much further upwards.

Sweepers are horrid pokemon to have on your team.  Universally frail, most sweepers don’t even need to worry about what they’re weak to- because their defenses are mediocre at best.  If there’s anything a sweeper fears, it’s a faster sweeper- and there’s always something faster with enough power to clobber the glass cannons that sweepers are.  Worse yet, one turn spent paralyzed will leave a sweeper helpless in the face of a crushing blow from virtually anything.

Know your sweepers and where they strike.

Infernape is a mighty sweeper, capable of a sweeping attack either from its special attack or from its physical attack- and in some cases from both.  However, its typing leaves it with obvious counters- anything Water, Ground, or Flying and bulky enough to take a hit from it can usually take it down.  Even pokemon that just have moves of those types can cripple it.  Once Infernape establishes itself as sweeping either physical or special attacks, the right choice of wall can bring it to a screeching halt.

Alakazam is fatal- but run it up against a pokemon whose weakness is Fire and it tends to stumble in most cases- and one decently-powered Dark attack will lay it flat.  Jolteon can’t take an Earthquake for anything, but outspeeds most opponents, and while Staraptor will horrify you when it hits you with Brave Bird or Close Combat, it mangles itself in the process, leaving it easy prey for a Quick Attack or Bullet Punch.

If you feel the need to break it before it can break you, and have something to put in the way of what shatters your cannon, pick a Sweeper.