Absol- The Disaster Pokemon
Ruby
Every time ABSOL appears before people, it is followed by a disaster such as an earthquake or a tidal wave. As a result, it came to be known as the disaster POKéMON.
Sapphire
ABSOL has the ability to foretell the coming of natural disasters. It lives in a harsh, rugged mountain environment. This POKéMON very rarely ventures down from the mountains.

Location
Ruby/Sapphire
Rt. 120, Rare to Find

Moveset
Swords Dance
Return Shadow Ball
Aerial Ace

Item
Lum Berry

Ability
Pressure

Nature
Adamant

Moveset Explanation
     Absol serves one purpose and only one- Sweep. 130 Base attack is absolutely gorgeous. Absol has all the characteristics of a typical Sweeper, including the traditional low defenses. However, there is one drawback to using Absol as a Sweeper- it's Speed is a little bit on the dismal side.
     Swords Dance is incredible on Absol, making that 359 Max Attack Double to 718 (and that's with a stalemate nature). Absol has crap in the way of Special Attack, though, so use Shadow Ball to make up for the loss of good Dark attacking. Aerial Ace is for Fighters and Return is just...well...Return.
     So that's Absol- a very powerful Physical Pokemon (not to mention he looks wicked too!).