Pokémon Go recently rolled out Gigantamax battles to players in all regions, with the super tough, 40-player raids launching last weekend with Charizard, Blastoise, and Venusaur up for grabs.
In Pokemon Go, the Mega Evolution system is governed by a resource called Mega Energy which players have to collect in order to Mega Evolve their Pokemon like Charizard, Venusaur, Blastoise, Gengar, ...