Jessie and James arrived at Pokémon Go using a Meowth balloon, alongside the traditional Team Rocket balloons that you might discover floating around you. You interact with the Meowth balloon just like you would with regular balloons. Instead of a growl, leader, or Team Rocket's Giovanni, you take on Jessie and James, the dynamic duo from the Pokémon anime and TV series. Both have a pair of Shadow Pokémon to use against you, and you have the chance to save them. You have to fight them both, and they have an Ekans and a Koffing to save you who can potentially be brilliant.
weaknesses
1st choice: Ekans and Koffing. You both have to fight, and they start with these two in every battle, guaranteed. Both are Poison-type, making them weak to Psychic and Ground-type attacks.
2nd choice: Jessie has Scyther and James has Sneasel. Scyther is a bug and flight type, which makes him weak to electric, fire, flight, ice, and rock type movements. Sneasel is a Dark and Ice-type Pokémon, making it weak to Bug, Fairy, Fighting, Fire, Rock, and Steel-type attacks. You'll probably want to focus on a Fire or Rock-type Pokémon to fight them.
3nd choice: Jessie has a Bagon and James has a Beldum. Bagon is a Dragon-type Pokémon making it weak to Dragon, Fairy, and Ice-type attacks. Beldum is a Steel and Psychic type, which makes him vulnerable to Dark, Fire, Ghost, and Ground type attacks. When fighting the last Pokémon for these two, you'll probably want to lean toward using a Fire or Dragon-type Pokémon.
counters
Fighting Jessie and James won't be too easy because you fight them back to back, fighting Jessie first, then James. But the reward is the chance to capture their shadows Ekans and Koffing, respectively. Jessie will use Ekans, Scyther, then Bagon against you, followed by James using Koffing, Sneasel, and Beldum. You want to fight a Pokémon that is capable of launching a psychic attack first, and then a Fire or Ground type attack soon after. A great choice for your Pokémon team includes using: Garchomp, Alakazam, Darmanitan, Metagross, Zekrom, Rhyperior, Gigalith, Reshiram, Heatran, or Tyranitar.
Any of the above choices will help you eliminate Jessie's Pokémon. Many coaches have said that removing these two is relatively straightforward and similar to tackling a Team Rocket growl, but it's still worth preparing.