In Pokémon Altair & Sirius, Dizasol is described as an evolution of Absol that was caused by anger at being blamed for the disasters it intends to warn people of, becoming the cause of those disasters instead.
Dizasol is no disaster when it comes to offensive tactics. It boasts base 115 Special Attack and 135 Attack, making it a fantastic mixed sweeper. This is further supported by a very wide and useful movepool, including Swords Dance through Level Up and Nasty Plot via Move Tutor to boost its already scary attacking stats through the roof.
Like most other offensive Pokémon, Dizasol suffers from low defenses and mediocre Speed. A good strike will see it off the field. Because Absol doesn't get Super Luck in Vega, Dizasol doesn't get it either - so it's stuck with Pressure for an Ability.
Dizasol is also very difficult to obtain - its previous evolution Absol can only be found in the Safari Zone in Nephrite City, and only in the center area - and even then it's a 1% chance to find one. Be prepared to invest a lot of time (and PokéDollars) to find and evolve one if this Pokémon is desired for a main story line team. After the main story line is over, both Absol and Dizasol can be found in Sphere Ruins.
Apart from the ridiculous time to obtain one, Dizasol is easily a good Pokémon to consider if one wants to cause catastrophes for NPC teams. No wonder Mosmero has one as his ace. As an extra fact, it shares a Base Stat Total with Arcanine ... that's really good.