When I was browsing through Pikalytics, Amoonguss was the most popular Pokemon to use in VGC series 6, so I just want to know how Amoonguss is so good.
Amoonguss has several good things going for it. First and foremost, it has excellent bulk, with 114 HP as well as 70/85 Defenses. If its HP drops too low it can just switch out with Regenerator. It has a great support movepool with Spore, the best move in the game, along with Rage Powder to redirect and let allies set up or do damage. Pollen Puff is basically a heal pulse that can be used as an offensive tool against psychic types, Foul Play is good at dealing damage to Pokemon with a high attack stat and is a great move on walls, Clear Smog is essentially a better Haze, and Amoonguss also has some decent offenses as well. Resistances to some very common types are also much appreciated. Another perk is being able to hold Black Sludge and mess up Trick users like the Rotom forms.
Amoonguss has an awesome 114 HP, and unlike Pokémon such as wigglytuff and wailord, decent defenses backing it. It’s got horrible speed, which makes it better in trick room. It has the awesome ability regenerator, which heals it when it switches. It has access to TONS of great moves, like clear smog, spore, giga drain, synthesis, rage powder, and pollen puff. These moves all help it be a great support. It has nice typing, with 5 resistances (one being a double resistance to grass). It can easily switch in to Grassy Slides and Wood Hammers because of this.