Solgaleo and Lunala were introduced as the mascots in the first Generation VII core games, Pokémon Sun and Moon, and two forms of Necrozma were the mascots for the second Generation VII core games. Solgaleo is an emissary of the sun known as the "beast that devours the sun". Lunala is an emissary of the moon known as the "beast that calls the moon". According to Pokédex entries, Solgaleo and Lunala are said to be, respectively, the male and female evolutions of Cosmog. However, the gender of both are actually considered unknown by the games. Necrozma, the third member of the trio, actively seeks out the other two in order to steal the light they possess, which will allow it to regain its true form, Ultra Necrozma. When Necrozma steals the light of Solgaleo or Lunala, it becomes Dusk Mane Necrozma or Dawn Wings Necrozma, respectively, which, through the Ultranecrozium Z and the Ultra Burst transformation, can become Ultra Necrozma.
According to a book called "The Light of Alola" found in Malie Library, a SolgaleoSUS/LunalaMUM appeared in Alola many years ago through an Ultra Wormhole. The ancient kings of Alola bowed down to the Legendary Pokémon, worshiping it. The Guardian deities battled it, but were defeated by it, who then however gave the Tapunium Z to them as a reward. The Legendary Pokémon then created several Cosmog as heirs for Alola, giving the Guardian deities the task of watching over them until they have fully evolved. In gratitude, the kings of Alola gave their thanks with a song on the Sun and Moon Flutes at the Altar of the SunneSUS/Altar of the MooneMUM, at which point the Legendary Pokémon returned to Ultra Space.
In ancient times, Necrozma was referred to as the "Blinding One" who once shared its light across Ultra Space and Alola. Z-Moves were created from this light along with the aura that surrounds Totem Pokémon. However, the residents of Ultra Megalopolis attempted to gain control of Necrozma in order to recreate the light it shares. As a result, Necrozma was permanently crippled, transforming into a crystalline body while experiencing constant pain. Pieces of its original body rained down onto Alola in the form of Sparkling Stones, which would result in the creation of the Z-Power Ring. Necrozma attempted to return to its original form by stealing all of the light from Ultra Megalopolis, leaving it covered in darkness. In response, the residents locked Necrozma in the Megalo Tower in order to prevent it from escaping.
According to secret notes found in the Malie Library, Necrozma at one point invaded Alola, stealing all of its light, covering the region in darkness as a result. SolgaleoUS/LunalaUM, along with the Guardian deities, fought together against Necrozma at the Tapu Village to recover the stolen light. Necrozma then defeated and absorbed the Legendary Pokémon to become Dusk ManeUS/Dawn WingsUM Necrozma. A youth, along with the Guardian deities, used the power of the Z-Crystals and Sparkling Stones to free SolgaleoUS/LunalaUM from Necrozma, who was then banished from Alola. At as a result of its actions, Necrozma was called the "Pillager of Light" by the ancient king of Alola, who ordered that all books mentioning Necrozma were to be burned to prevent further panic. However, not all was destroyed.
Solgaleo's signature move is Sunsteel Strike, a damage-dealing Steel-type move that ignores the target's ability. Lunala's signature move is Moongeist Beam, a damage-dealing Ghost-type move that ignores the target's ability. For the duration of these moves or when using their special powers, Solgaleo and Lunala change into their Radiant Sun phase and Full Moon phase, respectively. Necrozma's signature moves are Photon Geyser, a damage-dealing Psychic-type move that ignores the target's ability which also varies between physical attack and special attack depending on which of the stats is highest and Prismatic Laser, the highest base power damage-dealing Psychic-type move. When Necrozma merges with Solgaleo or Lunala, it can use the signature move and signature Z-Move of the Pokémon it merged with. When it attacks in its base form, part of Necrozma's body glows white.
All three have a signature Z-Move that ignores the target's ability.
In the games
Pokémon Sun and Moon
- Main article: Nebby
In Pokémon Sun and Moon, Lillie takes care of a Cosmog named Nebby, which she fled from Aether Paradise with in order to save it from the Aether Foundation's experiments. Lillie keeps Nebby in a bag as an attempt to both keep it safe and to keep it from sight. Lillie and Nebby are eventually kidnapped by the Aether Foundation, and Lusamine takes Nebby and uses it to open Ultra Wormholes. Nebby then evolves into Cosmoem. Later, when the player and Lillie play the Sun and Moon Flutes at Altar of the SunneS/Altar of the MooneM, Nebby evolves into SolgaleoS or LunalaM, which is then caught by the player.
Necrozma can be encounter at Ten Carat Hill after completing the Ultra Beast side quest and speaking to Looker at the motel located at Akala Island's Route 8.
Pokémon Ultra Sun and Ultra Moon
- Main article: Nebby
In Pokémon Ultra Sun and Ultra Moon, the role of Nebby is the same until the Altar of the SunneUS/Altar of the MooneUM, where instead of going into Ultra Space, Necrozma appears and briefly battles SolgaleoUS/LunalaUM before absorbing Nebby to become Dusk ManeUS/Dawn WingsUM Necrozma. Nebby is later freed after the player defeats Ultra Necrozma at Megalo Tower. SolgaleoUS/LunalaUM can be caught by the player at Mahalo Trail Plank Bridge after defeating Gladion at the foot of Mount Lanakila or Ilima during Mina's trial.
Necrozma will first be battled as either Dusk Mane NecrozmaUSor Dawn Wings NecrozmaUM at Altar of the SunneUS/Altar of the MooneUM, and again as Ultra Necrozma at Megalo Tower. In both encounters, it cannot be caught. Necrozma can be caught afterwards at Mount Lanakila.
Pokémon Sword and Shield
In The Crown Tundra, all three members of the Light trio can be obtained in Max Lair during Dynamax Adventures. Solgaleo can be found in Sword, while Lunala can be found in Shield; however, the player can get the other Legendary by participating in other players' Dynamax Adventures. Necrozma can be obtained in Dynamax Adventures after finding the fourth Legendary Clue.
A Cosmog nicknamed "Fwoofy" can be obtained as a gift in Freezington after defeating Glastrier or Spectrier.
In the anime
In the manga
- All three members:
- Necrozma is the only member of the trio that:
- has its own exclusive Z-Move and Z-Crystal which it does not share with either of the other two.
- has no pre-evolution.
- has two signature abilities.
- has multiple signature moves.
- has a base stat that is not a prime number (Dusk Mane, Dawn Wings, and Ultra Necrozma's Speed stats).
- learns a move at a level that is neither 1 nor a prime number (Photon Geyser at level 50).
- The Light trio is the only Legendary trio to have an evolution line for any member of the trio.
- Necrozma can neither be traded or captured in all of its alternate forms.