Legendary Powermon

From Bulbapedia:
Legendary Pokémon are a group of incredibly rare, and often very powerful Pokémon. 
While in English, all are typically grouped under the banner of "legendary", there are three distinct terms in Japanese that are used to refer to them. One, 伝説のポケモン densetsu no Pokémon, literally "legendary Pokémon", refers to Pokémon such as Kyogre and Groudon, who are featured prominently in the legends of the Pokémon world. A second, 幻のポケモン maboroshi no Pokémon, literally "illusory Pokémon", refers to Pokémon seen so rarely, such as Mew, that some question their very existence. This term was translated in the Generation IV games as "mirage Pokémon", in reference to the various myths of Sinnoh, and many consider it to refer to Pokémon that are restricted to Nintendo events, not available during the course of normal gameplay. The third and newest term is 神話のポケモン shinwa no Pokémon, literally "mythical Pokémon", which refers to the Pokémon which are spoken of as the creators of the Sinnoh region. 
==Region I Legendary Powermon==
===Guardian Trio===
Main articles:
*Neveinx
*Griffolt
*Arsecore
The Guardian Trio, who protect all valuable things, are the first Legendaries in the Kroel Pokédex order, as well as the first Legendaries to be encountered. They are similar to the Legendary Birds of Kanto, in that they share the same type combinations, abilities, and base stats, as well as similar movesets. Due to their being part of Region I, they are accessible from all regions of Kroel.
Unlike some of the later trios, the members of the Guardian Trio are able to manifest in physical forms, meaning that they do not require Avatars. In Pokémon: Bronze, their trio master is Zizclone, since it is not possible to capture Zizclone until all three of the Legendary Guardians are captured.
===Darkness Duo===
Main articles:
*Svalad
*Nosferatwo
==Region II Legendary Powermon==
===Draconic Trio===
Main articles:
*Garaday
*Spyraco
*Arkorion
===Wolf Duo
Main Articles:===
*Hatoom
*Loskoll
===Crossoton===
==Region III Legendary Powermon==
===Hive Trio===
Main articles:
*Sultaranta
*Soleomoth
*Czarzzazin
===Storm Duo===
Main articles:
*Raijun
*Raykon
===Dominion Triad===
Main Articles:
*Leviathide
*Trehemorth
*Zizclone
The Dominion Triad are the version mascots of Iron, Copper, and Bronze, and among the most pivotal Legendaries in the storyline, apart from Svalad and Nosferatwo. They are referred to in the games as the "primeval Pokémon," and are seen as the demon analogs of Kyogre, Groudon, and Rayquaza from the Ruby and Sapphire versions.
In the anime, these three Powermon are the first to appear, and the first to be shown to have Avatars.
===Auroreon===
===Astronox===
==Region IV Legendary Powermon==
===Creator Trio===
Main articles:
*Ranima
*Zeukico
*Odesker
===Monster Duo/Trio===
Main articles:
*Parephon
*Ekhimere
*Moira
In the Iron and Copper versions, Parephon and Ekhimere are represented as a duo, and are widely considered the ancestors of all Pokémon. With the introduction of Moira in the Bronze version, however, there has been much debate over whether it should be represented as part of the trio or a standalone legendary. Much evidence, such as the fact that they all share the same base stats, ability, and primary type, points to this possibility. However, as Moira is an event legendary, it is generally considered as a standalone.
Parephon and Ekhimere are version-exclusive (Parephon in Iron and Ekhimere in Copper), but they are both obtainable in Bronze, while Moira is only obtainable in the Bronze version. All three of them are involved in an event in Bronze, in which the trainer has to defeat at least the first two of the trio.
===Four Horsemen of the Apocalypse===
Main articles:
*Kofragon
*Dismonark
*Grimeeper
*Skeletox
===Abbalordd===
===Royalty Duo===
Main Articles:
*Biolomina
*Melanocetos
===Deomega===
==Region V Legendary Powermon==
So far, there has been only one Legendary Powermon for the fifth region: Volchaozor. However, as there is more than one legendary for Generation V, it is certain that there will be more Legendary Powermon revealed in the future.