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 battling. 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. Extremespeed is a huge deal, since 85 Speed is average for a sweeper. Comparatively, Dizasol is a lowkey Mega Absol, though the differences would be taking up a Mega Slot and Mega Absol having higher Base Speed than Dizasol. However, Mega Absol does not gain slightly noticeable bulk compared to Dizasol.
Like most other offensive Pokémon, Dizasol suffers from low defenses and mediocre Speed (Though, Extremespeed compensates it). Because Absol doesn't get Super Luck in Vega, Dizasol doesn't get it either - so it's stuck with Pressure for an Ability (Although, in Procyon and Deneb, it does happily get Super Luck).
Dizasol is 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 in the main story line. 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 that don't have a Fighting or Bug type to answer. No wonder Mosmero has one as his ace. As an extra fact, it shares a Base Stat Total with Arcanine.