"When It gets exposed to plenty of sunlight, the leaves ringing its body begin to spin around. This Pokémon’s dancing is renowned in the southern lands."
The Johto region did many things for Pokemon, including giving certain Pokemon news ways to evolve, even if they were already evolved in some cases. Gloom can evolve into Vileplume, but in Johto, we got the Sun Stone, which allowed it to evolve into Bellossom. This Pokemon in both looks and stats was very different than Vileplume, and was a perfect example of how branching evolution can be.
Bellossom's Basic Attacks are Razor Leaf and Acid, while its Special Attacks are Petal Blizzard, Leaf Blade and Dazzling Gleam.