Absol is a Pokémon who is built for straight up attacking or Baton Passing set-up moves to its team-mates. It has good attacking stats so it can hit hard, and its movepool is very wide to cover its weaknesses well. It also has an evolution in this game, which is the incredibly powerful Dizasol.
Unfortunately Absol does not have the best bulk and its HP stat is terrible, alongside a mediocre Speed stat. Any super-effective hit is going to knock a huge chunk of its health off very quickly - and that hit will probably strike first. Absol is also vastly outclassed by its much better evolution.
If one desires to use an Absol then they will have to search in the center area of Nephrite City's Safari Zone - and even then it is only a 1% encounter rate so this Disaster Pokémon will cause disasters to Trainers planning to hunt for one.
Overall, Absol can be potentially useful - but in most circumstances this will only happen if it evolves into Dizasol.