Like Absol, Baizeast is based on the mythical Bai Ze, bearing a strong resemblance to the creature, yet not possessing the disaster-predicting powers.
With 115 Special Attack, and being able to learn a wide variety of moves, Baizeast is the best offensive Pokémon early game. It is also capable of taking on the role of a Support with moves like Light Screen, Reflect and Safeguard later on.
Unfortunately, Baizeast is also short on defenses, especially on the physical side. For an offensive Pokémon, it also has a very low Speed stat, which means it will be outsped by most offensive threats and easily knocked out without the protection of Light Screen or Reflect.
In Procyon and Deneb, Baizeast will be much more powerful, receiving an additional Fairy-typing, new moves, and the Analytic ability which compensates its low speed by offering it much more power.