Trainer battles are at the heart of most Pokemon games, even those outside the mainline series, like Pokemon GO. Trainers who want to test their mettle can do so on the Battle League, where they can go head-to-head with other similarly-ranked players in battles using a roster of three of their best Pokemon. It has three leagues that rotate each season, with the most challenging one being the Master League, as it has no Combat Points (CP) limit. The Pokemon GO World of Wonders season’s Master League is right around the corner, and there are various rewards and updates that players to expect.