Team GO Leader Sierra is one of the hardest challenges a trainer can take on in three Leaders Cliff, Arlo and Sierra, making it worthwhile to try and take them down this month.

Team GO Rocket's forces are split into three types: Grunts, Leaders and the Boss. The Leaders offer a much tougher challenge than when facing Grunts and all have high Pokémon. This means the only way to consistently beat them is to select a line-up of three Pokémon that can counter their teams and are super-effective against the different options they can use. This is the case for Sierra, making it vital that you know her team's weaknesses and the best counters to them.

Sierra's Team & Counters In Pokémon GO (May 2025)

Fire And Ground Pokémon The Key

Sierra is one of the toughest tests in Pokémon GO due to her team covering so many different types, making it hard to counter. She will always use three out of the same seven Pokémon, but these change from battle to battle. However, what does make this battle easier is her team at the start of May 2025 is the same as Sierra's team in April 2025 in Pokémon GO. You need to select three Pokémon for each battle with Sierra, but it is possible to win the battle with just one or two Pokémon.

The only Pokémon that she will always use is Poison- and Bug-type Skorupi, which she starts with. This gives you an advantage as you pick a counter that will always dominate it. After this, though, it gets more tricky as you can't guarantee what she will use for the second and third waves.

After Skorupi, Sierra will use either Water-type Milotic, Fire-type Ninetales, or Steel- and Grass-type Ferrothorn. Regardless of which of the above is used, her third Pokémon will also be completely random out of Dark- and Fire-type Houndoom, Poison- and Ground-type Nidoqueen, or Poison- and Dark-type Drapion.

Two types of Pokémon are key to beating Sierra this month: Fire-types and Ground-types. Fire Pokémon can dominate both her lead Skorupi and Ferrothorn, who only has two weaknesses. Several Fire-type Pokémon are capable of this role, but my favorite remains Ho-Oh. The Generation 2 Legendary remains one of the best attackers in Pokémon GO and is a great choice to start the battle for you.

Milotic is the only Pokémon in Sierra's team that isn't weak against either Fire- or Ground-type attacks, making it the wild card in her line-up.

After Ho-Oh, you want a strong Ground-Pokemon that you can switch to if Sierra uses Ninetales in her second wave and a great choice is Groudon. It also has the rare advantage of being super-effective against all of the leaders final possible Pokémon: Houndoom, Nidoqueen, or Drapion. Against any of the three, Groudon will be able to make quick work of them. As a last choice, it is good to have either an Electric-type or Grass-type to Milotic in case it is selected, such as Zapdos or Magnezone, with either being able to do the job.

Rewards For Beating Sierra In Pokémon GO

One Step Closer To Giovanni

Beating Sierra in Pokémon GO this May 2025 gives you a host of rewards, making it worthwhile. If you want to take on Team GO Rocket Boss Giovani this month, you will have to beat Sierra first alongside the other two leaders. You will also receive a number of items. If you space in your Egg Inventory, one of the rewards will be a 12km Egg. These are the rarest eggs currently available in Pokémon GO and contain some of the hardest to find Pokémon.

Sierra's Pokémon are all Shadow variants, making them harder to defeat, but more valuable if you catch your own at the end of the battle to use going forwards.

In addition to the rare egg, you will be given items chosen at random out of 4x Revives, 2x Max Revives, 4x Hyper Potions, 2x Max Potions, or an Unova Stone. Finally, you will receive an encounter with one of Sierra's Pokémon immediately after the battle. For this month, it will be Shadow Skorupi.

Sierra remains a tough battle for all trainers in Pokemon GO in May 2025. However, by using Fire-types and Ground-types, you can make it a lot easier.