The Pokémon Go Fighting League consists of three divisions. The Great League, the Ultra League and the Masters League. They work the same in that players have three different Pokémon to use in a battle against another player, but the potency of the Pokémon you can use changes. For the Ultra League, you can only use Pokémon with a CP equal to or less than 2500. While all three divisions work the same, there are a few differences.
Each player wins their first five Championship Battles for free. However, after that, players need to secure their next set, which means they have to walk five kilometers before heading home. You can get around this by purchasing a Premium Raid Pass, and only need to travel two kilometers. Either way, you will need a distance to participate in the battles. Everyone can only enter three sets per day for a total of 15 fights.
Because you can use Pokémon that have a CP of 2500 in the Ultra League, you have a wide variety of choices available to you in battle. These teams are going to vary in difficulty due to their potency, and you can expect to see several powerful trainers using Pokémon like Giratina (Altered), Regice, Swampert, Registeel, Togekiss, and many more.
Your rank increase varies depending on where you are. For example, for ranks 1-5, you can win or lose your battles and keep moving forward. However, when you are in the fifth rank, if you want to progress, you have to win battles. If you lose a battle from rank five to rank seven, you do not downgrade. But, when you reach rank eight, you need to get up to 2 points to advance. Winning and losing are important, and losing battles means you go down one rank.
The rewards for the Battle League remain the same throughout the season. You have the chance to meet several different Pokémon if you win a certain number of battles in your rank. For example, if you win four Battles and are above Rank 4, you have the chance to encounter a Scraggy, a new Pokemon that you can only encounter by participating in Battle League. These are the Pokémon that you are lucky enough to encounter for each rank.
- From one to three: Machop, Oshawatt, Snivy, Snorlax, Tepig
- Ranks four to six: Machop, Meditite, Oshawatt, Scraggy, Skamory, Snivy, Snorlax, Tepig
- Ranks 7 to 10: Deino, Lapras, Larvitar, Litwick, Machop, Meditite, Oshawatt, Scraggy, Shieldon, Skamory, Snivy, Snorlax, Tepig
From the start of the Ultra League, you have two weeks to complete and reach Rank 10 and reap the rewards. The preseason is going on right now, and you have until February 10 to 24 to participate. Niantic will adjust the game based on player feedback on the preseason when the first season releases. The new season also brings new rewards, like Libre Pikachu.