While it is not known to evolve to or from any other Pokémon, it has three different forms that are based on the game it is in. In Pokémon Vega, Asphere is only normally obtainable in its Vega Form.
Although planned to appear in Pokémon Deneb and Procyon, it is currently unknown whether it will get new forms.
As the most powerful Pokémon in the game, possessing stats roughly equivalent to Arceus, Asphere is very capable in every field. In its' Vega Forme, it has balanced Attack, Defense and Special Defense, with its Special Attack and Speed being as high as those of its other Formes. Coupled with its diverse movepool and powerful signature move, Nova Inferno, the only other Pokémon in the game with similar offensive prowess is Mewtwo, which it does not even have Psystrike in this game funnily enough. Due to its extremely wide movepool and access to both Swords Dance and Nasty Plot, unresisted STAB Type with Raze Earth to slay Heatran, among many other useful moves, it is a very versatile Pokémon that allows for many different playstyles, from standard sweeper to even Defensive tank on both fronts due to having Marvel Scale.
Overall, this Pokémon completely rules as the most powerful Pokemon in existence in Vega, even resembling strengths from both Arceus and Mega Rayquaza combined.
While Asphere itself is encountered at Level 90, the wild Pokémon in the Sphere Ruins' lower floors can be encountered at even higher levels, up to and including Level 100.
However, this is not true in the Vega Minus version. Asphere is at Level 80 when encountered while the wild Pokémon at the lowest floor can be found at Level 70 maximum.
Asphere's other signature move, Icebolt Wave, can only be learned by it in Altair/Sirius, as it is the signature move of those Forms. As such, Turner's clones do know the move.
Asphere's stat total of 720 is the highest of all the games it's been in, equal to that of Arceus.
The Asphere clones used by Turner in the final battle have base stats far higher than what's reasonable for an obtainable Pokémon. This may have been intended to simulate EV-trained versions of them.
Asphere is one of a select few Pokémon shown to be capable of human speech in the game. The others are Mewtwo and Aldina.
Turner's clones do not seem to be able to speak, only letting out primal roars during their rampage at the end of the game.
In Pokémon Altair & Sirius, Asphere's true identity is suggested to be that of a guardian deity, or possibly a ruler, of an old civilization that lived in Sphere City. This is shown through Braille writings found within the Sphere Ruins.
In Pokémon Altair/Sirius, Gordon will mistakenly call Asphere "Asmodeus", which is actually the name of a mythological demon king. This is likely only a gag without any actual relevance.
In Vega's Mirage Battles System, Sylvia uses a Vega Form Asphere.
Design Origin[]
Asphere seems to represent various stars and stellar atmospheres. Its Altair Form, possessing the power of the constellation Aquila, has a Dragon/Ice typing. It is named after Altair, the brightest star in the Aquila constellation while its' Sirius Form is a Dragon/Electric-type, and is likewise named after the brightest star of Canis Major. Finally, its Vega Form is named after the brightest star of Lyra, hence the Dragon/Fire typing.