In Pokemon Black and White, two new evolutionary families were introduced. In Black, you could get Cottonee, the Cotton Puff Pokemon, while in White, you could get Petilil, the Bulb Pokemon. Both of them are competitively used Pokemon. Whimsicott, which is Cottonee’s evolution, gets Prankster as its regular ability and Infiltrator as its hidden ability, both of which can be annoying to your opponent. Prankster gives priority to status moves and Infiltrator allows moves to pass through Reflect, Mist, Light Screen, and Substitute. And Lilligant gets the useful ability of Own Tempo. Lilligant can use this better than other Pokemon because she can have Petal Dance as a move. Petal Dance is a powerful special move with 120 base power. Unfortunately, after you start using it, you will continue using it for 1 or 2 more turns before you become confused. However, if you have Own Tempo, you will not become confused. Both of these Pokemon become version exclusives in Sun and Moon, with Cottonee being exclusive to Sun and Petilil to Moon. But which one is better to use?
First off, if you picked Rowlet, there’s not a good reason to use either of these Pokemon, especially Petilil. You could use Cottonee, but only because it’s part Fairy type. But even then, there are Fairy types and you shouldn’t use multiple Pokemon of the same type. But if you picked Litten or Popplio then getting a Grass type such as Petilil or Cottonee would be good. If you picked Popplio, stick with Petilil. Like I said, it’s not good to have multiple Pokemon of the same type and with Primarina being a Fairy type and Whimsicott also being a Fairy type, it would be better to stick with the pure Grass type (but if you’re playing Sun, there are other pure Grass types such as Fomantis and Bounsweet). If you picked Litten, then either would be good. But which one is better for your travels through the Alola region?
The thing about Litten is that it has difficult with all of the kahunas. Being a Fire type means that it has difficulty with Olivia and Hapu, and once it becomes a Dark type, it’s weak to Hala’s Pokemon and its Dark type moves won’t do much to Nanu’s Pokemon (although luckily Litten is a Fire type, which does neutral damage to Dark types). So, getting a Whimsicott would be good for Hala and Nanu. Both of them would be good for Olivia and Hapu. And against the Elite Four, Whimsicott would still be good against Hala, both would be good against Olivia, and they would be about the same for Acerola and Kahili. Any way you look at it, it seems obvious that you should get a Cottonee. But this Pokemon can’t be perfect, right?
Yes, no Pokemon is perfect. Although Whimsicott’s Fairy typing gives it immunity to Dragon type moves as well as taking normal damage from Bug, and resisting Dark and Fighting type moves, it does have some drawbacks. Whimsicott’s biggest weakness is Poison types. They are doubly effective against it, and Poison resists both Grass and Fairy type moves. In addition to that, it gains a weakness to Steel, which it also cannot deal with well. Luckily, Plumeria and Molayne are the only users of Poison and Steel types, and they’re Champion Challengers.