The Iron-Masked Marauder

Masaru Philip Tamai (better known as "The Iron-Masked Marauder" or "Vicious") is from Arborville in the Johto region. He's a former member of Team Rocket and is now a member of the Tekiyoku. He's a Steel Manipulator.

Present
The Marauder first showed up at the end of Episode 15 in Ecruteak City in the Johto region. He suddenly appeared as Alain, Ash, and Casey were about to run to an old baseball field there that Casey loved, in order to stop Archie from destroying it. Archie was there terrorizing the city, and he was about to destroy the field because Casey just tried to attack him with her Beedrill, followed by him killing it. He found out that Casey liked that baseball field, so he ran to destroy it. Marauder appeared to fight them and keep them from stopping Archie.

Alain and the rest of the Mokusetsu were there in the first place to find the Bug Plate, Tamamushi. A fight began with Alain and Ash holding off the Marauder. Marauder revealed that he and Archie were there because Lysandre wasn't happy with the Tekiyoku's reign over the 7 regions, so he ordered them to take things up a notch.

Suddenly, flames erupted from the field, signaling that Archie just burned the field down. This made Casey cry while Lyra tried to comfort her.

Archie joined in the fight. It ended up with Archie sprouting a giant, steel hammer with Blacksmith. However, Alain ended up using Graceful Descent to slam Archie down to the ground. Alain then got the hammer from him and then swung it right into Marauder's gut. After this, Marauder and Archie retreated.

As they were leaving, they discovered Dawn, who wasn't doing a very good job at hiding during the fight. They seized Dawn and went back to the rest of the Mokusetsu. They gave an ultimatum; either Alain gives up the Bug Plate, which they saw he had just found, or they kill Dawn. Frustrated, Alain agreed to give up the Bug Plate. Marauder and Archie then left with the Plate.

Naming

 * His three actual names, Masaru, Philip, and Tamai were all randomly selected from name generators.
 * His primary nickname, The Iron-Masked Marauder, is what he's referred to in the English dub of the anime.
 * His other nickname, Vicious, is his Japanese name in the anime. According to his Japanese voice actor, Shirō Sano, it comes from Sid Vicious, the late bass player of the English punk rock band, Sex Pistols.

General

 * His birthday, May 8th, was randomly selected.
 * The Iron-Masked Marauder is from Arborville (in this series, not in the official Pokémon anime). Archie is from Fortree City. Both places are entirely similar in structure, having houses that are only built in trees. Both of these people appeared together in Ecruteak City to terrorize the city and fight the Mokusetsu. This was not planned by Nocturnal Jay at first and wasn't discovered until after he wrote that entire Johto portion of the series.