In the games
Maxie is the head of Team Magma. In Pokémon Sapphire/Alpha Sapphire Maxie helps the player against Team Aqua. He doesn't have an active role in the storyline and can't be battled.
In Pokémon Ruby/Omega Ruby he first appears in the Oceanic Museum in Slateport City, trying to steal the Devon Goods from Captain Stern. Later, Team Magma members steal a Meteorite from Professor Cozmo in Meteor Falls, and use it to try to cause Mt. Chimney to erupt. Then, after Courtney raids the Weather Institute, Maxie steals the Blue Orb from Mt. Pyre. Later, he and the Team Magma members turn up in Slateport again as Captain Stern announces a discovery he has made about a seafloor cavern. Team Magma promptly steals the Submarine Explorer 1 that Captain Stern has built and goes for the Seafloor Cavern to awaken Groudon.
In Pokémon Emerald Maxie tries again to dry Mt. Chimney's lava pool via the meteorite from Meteor Falls, but this time he is looking for Groudon inside the volcano. After this first, unsuccessful attempt, Maxie sends Team Magma members to make a new, secret hideout inside the volcano, where he finally awakens Groudon using the Blue Orb stolen at Mt. Pyre. However he loses the control over the legendary Pokémon. Later Team Magma raids the Mossdeep Space Center, trying to use the rocket fuel to make Mt. Chimney explode. The protagonist comes just in time to stop him, but as Tabitha is teaming up with Maxie, Steven is forced to team up with the player to stop Team Magma. When defeated a third time, Maxie sees the error of his ways, later disbanding Team Magma and attempting to stop Groudon and Kyogre's fight.
In the animeMaxie appeared in Gaining Groudon and The Scuffle of Legends. Maxie's goal was to expand the land of Hoenn believing that if so, the land would be peaceful. But at the end of the latter episode, Maxie realized the errors of his ways and finally changed his beliefs, now believing that the land of Hoenn is supposed to be kept as is.
Like his rival, Maxie is noticably more evil in his manga appearance. Despite operating Team Magma from a cave and being a heavy alcoholic, he is very effective in setting his plans into motion. He also possibly knows more about the legends than Archie, making a priority to steal the two orbs that control Groudon and Kyogre, giving him an edge over Aqua towards the climax.
When Magma had stolen Captain Stern's submarine and Aqua the key to use it, the two gangs called a temporary truce and dove to the Seafloor Cavern where they split up to search for their desired Pokemon, Archie finding his first. Maxie finally found Groudon nearly a day later but was still able to control both beasts with the Red and Blue Orb. After Archie sent one of his men to steal the Red Orb,Maxie and Archie were possessd by the Orbs powers during a fight with Ruby and Sapphire and rose to Sootopolis to fight each other ending with Rayquaza descending to put a stop to Groudon and Kyogre.
Maxie and Archie, no longer possessed went insane, teamed up for real and resorted to genocide with Maxie killing Norman. After they are defeated once again, they attempt to escape with Wallace's car which is halted by an electircal barrier. Ruby's Celebi flies in to recover the orbs and the two leaders were presumed dead after that point. Maxie was later supposedly killed by Archie in a dispute.n the Omega Ruby & Alpha Sapphire chapter, Maxie is revealed to still be alive. Alongside Archie, Maxie travels to the Kanto region, where they find Bill, who had obtained the shattered remains of the Red and Blue Orbs from Team Rocket in the FireRed & LeafGreen chapter. They attack Bill and steal the shards from him, which have now regenerated back into their forms as Orbs. They steal Bill's boat and use it to travel back to the Hoenn region. Upon arriving, Maxie and Archie are approached by Red and Green, two Kanto Pokédex holders that are friends with Bill. Red and Green attack Maxie and Archie to avenge their injured friend and retrieve the stolen Orbs. To combat their opponents, Maxie and Archie reveal they have learned to use Mega Evolution and use it to face the two Pokédex holders, who counter with their own Mega-Evolved Pokémon.
The battle is interrupted by Blaise and Amber. Although Blaise finds the new appearance of their leaders suspicious, Amber reveals that they summoned Groudon and Kyogre from their resting places with the power of Hoopa. Immediately after, Groudon and Kyogre appear, having followed the presence of the Orbs. Maxie and Archie use the Orbs to revert Groudon and Kyogre into their Primal forms, greatly increasing their power to the point where they easily defeat Red and Green. Groudon and Kyogre's rampage is interrupted by Ruby and Emerald, who attempt to fight the super-ancient Pokémon but are unable to damage them. Maxie and Archie use Groudon and Kyogre to easily blast Ruby and Emerald out of the sky, easily defeating them. With their opponents on the ground, Maxie and Archie gloat over their victory and reveal that their return is all for the sake of saving the planet from the meteoroid threatening to destroy it.
Later, at the Meteor Village, Maxie trains alongside Archie in order to teach Groudon Precipice Blades. They were given a training space by the village Elder, who agreed to help in their attempt to stop the meteoroid. After a day, Maxie and Archie finish their training and exit their training space. Just as they do so, Rayquaza sees Groudon and Kyogre through Hoopa's ring and attempts to attack by flying towards the ring. The experience scares Hoopa, causing it to accidentally send Rayquaza to another ring connecting the village to Route 120. Maxie and Archie chase after Rayquaza and arrive at Route 120 by forcing their way through Hoopa's ring. They decide to test the moves Groudon and Kyogre learned on Rayquaza, but are interrupted by large chunks of the meteoroid falling down on them. To destroy the chunks, Maxie, Archie, Ruby, and Sapphire combine the powers of Primal Groudon, Primal Kyogre, and Rayquaza into a single attack.As the three super-ancient Pokémon's attack struggles to destroy the meteoroid chunk, Maxie and Archie's bodies run out of energy and begin to break down. The combined attack eventually breaks the meteoroid chunk into pieces, which fall onto Groudon and Kyogre, knocking them out. After watching from afar, Blaise and Amber go down to see if their leaders are safe, only to find them both in the process of fading away. Maxie and Archie explain to the two that after their "deaths", their spirits ended up in another world, where they at one point melded together and became one. After a hole to the real world was opened, an unknown voice called out to them, asking to protect the planet. After escaping from the world, they regained their bodies, albeit slightly different, gained Mega Evolution, and stole the orbs from Bill in order to save the planet from destruction. Just as they disappear completely, Maxie and Archie ask their subordinates to protect the planet.