Main or Special trios
Weather Trio
The weather trio is a fan term applied to the three ancient Legendary Pokémon from Hoenn legend—Groudon, Kyogre, and Rayquaza. In the games, they are referred to as the super-ancient Pokémon (Japanese: 超古代ポケモン super-ancient Pokémon), and another fan nickname is "elemental trio".
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Creation Trio
The subject of this article has no official name.
The name currently in use is a fan designator; see below for more information.
The creation trio is a fan term used to refer to three powerful Legendary Pokémon of the Sinnoh region: Dialga, Palkia, and Giratina. Other fan terms include deity trio and dragon trio.
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Tao Trio
The subject of this article has no official name.
The name currently in use is a fan designator; see below for more information.
The Tao trio is a collective fan term used to refer to the three powerful Legendary Pokémon of the Unova Region: Reshiram, Zekrom, and Kyurem. Other fan terms include Tao dragon trio and energy trio.
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Aura Trio
The subject of this article has no official name.
The name currently in use is a fan designator; see below for more information.
Aura trio is a fan term for the legendary trio of Kalos, consisting of Xerneas, Yveltal, and Zygarde, the first two of which are found at the Team Flare Secret HQ in Pokémon X and Y, respectively.
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Light Trio
The subject of this article has no official name.
The name currently in use is a fan designator; see below for more information.
Light trio is a fan term for the Legendary trio of Alola that consists of Solgaleo, Lunala, and Necrozma.
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Other Legendary Trios
Legendary Birds
Legendary birds (Japanese: 伝説の鳥ポケモン Legendary bird Pokémon) is a collective term used to refer to the trio of Articuno, Zapdos, and Moltres. They are also known as the winged mirages (Japanese: 幻の翼 phantom wings). In the Crown Tundra, their Galarian versions have been referred to as legendary wings.
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Legendary Beasts
Legendary beasts (Japanese: 伝説の獣ポケモン Legendary beast Pokémon) is a collective term used to refer to the trio of Raikou, Entei and Suicune.
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Lake Guardians
The lake guardians (Japanese: 湖の神々 lake gods), or lake trio, is a term used to describe the Legendary trio residing in the three lakes of Sinnoh: Uxie, Mesprit, and Azelf.
Forces of Nature
The Forces of Nature (Japanese: 大自然の力 forces of nature) is a collective term to refer to the all-male Legendary trio of Tornadus, Thundurus, and Landorus. They are also known by fans as the kami trio, cloud trio, or Legendary genies.
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As such, we can tell that the important or main/special trios all have fan terms while "other legendary trios" have been referred by that name in anime or shown in games.
Duos
Tower duo
The tower duo is a fan term for the Legendary duo of Johto that consists of Lugia and Ho-Oh. Lugia and Ho-Oh are often regarded as polar opposites.
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Eon duo
The eon duo is a fan term for a Legendary duo of Hoenn that consists of Latias and Latios, which are also that region's roaming Pokémon.
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Lunar Duo
The lunar duo is a fan term for a duo of Sinnoh that consists of the Legendary Cresselia and the Mythical Darkrai.
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Hero duo
The hero duo is a fan term to describe the main legendary duo of Galar, consisting of Zacian and Zamazenta.
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So, all of these duos name are fan term.
Hope this helps. Comment if anything missing.
