Gaiien Region: Companionship is Magery: Nimbval, Grimass, and Celestiule

Nimbval and Grimass obey the usual rules of Pokémon breeding with one exception: a Nimbval and a Grimass parent will produce an egg for an entirely new Pokémon instead of the offspring taking the form of the mother. However, the dual and opposing natures of Nimbval and Grimass are well-known and common elements in media going back to ancient times, and finding a compatible pair is a rarity. Celestiule were the heralds or mounts of various deities.

#030 - Nimbval
Noble Pokémon
Light-type
It features prominently in mythology as a herald of good fortune. It has a heroic nature but is easily bamboozled. It can hybridize with the dark-type grimass to produce celestiule offspring.
Base Stats: 100/70/100/80/100/50
Ability: Consecrate (activates light-type environmental effect on switch-in) / Magic Friend (adjacent ally may periodically have lowered stats returned to normal), Hidden: Healer
Learnset: Tackle, Stomp, Dazzle, Peaceful Glow, Illuminate, Sunbeam, Dawn Call, Rebuke, Light Screen, Morning Sun, Helping Hand, Low Kick, Bestow, Heal Pulse, Herd Call, Refresh

#031 - Grimass
Nightmare Pokémon
Dark-type
It has a frightening appearance and a bad reputation. In mythology, it was born from the vengeful spirit of a mistreated animal. It can hybridize with the light-type Nimbval to produce Celestiule offspring.
Base Stats: 70/100/100/50/80/100
Ability: Defile (activates dark-type environmental effect on switch-in) / Nightmare Moon (speed increases under night/darkness effect), Hidden: Anger Point
Learnset: Tackle, Stomp, Lick, Assurance, Beat Up, Screech, Bite, Crunch, Pursuit, Snatch, Dragon Rush, Outrage, Taunt, Torment, Herd Call, Low Kick, Double Kick, Night Call, Grudge

#032 - Celestiule
Messenger Pokémon
Light/Dark-type
It is a hybrid produced by a Nimbval and a Grimass parent. They are rare to see because the parents’ natures are often inimical. Its appearance reflects the current sky conditions, and will change with the time of day and weather.
Base Stats: 83/83/83/83/83/83
Ability: Cloudsdale (weather ball’s type changes with weather/time of day) / Cloud Nine, Hidden: Barometer (stats or decrease based on total changes on field)
Learnset: Tackle, Stomp, Shadow Call, Shadow Bolt, Dark Pulse, Weather Ball, Dazzle, Peaceful Glow, Sunbeam, Illuminate, Dawn Call, Night Call, Low Kick, Morning Sun, Moonlight, Cosmic Power, Starlight Wave, Moonblast


Notes: Ponies, and fakemon that would instantly fall afoul of Nintendo’s swear filter and E rating. :B

These three have changed quite a bit since their initial appearance in 2005 or thereabouts. Celestiule originally had some complicated breeding rules depending on which of Nimbval or Grimass was the mother or father, and two Celestiule of the dark gray and light gray varieties could (rarely) mate to produce a second-generation Celestiule (much like how real-life mules are usually sterile, but sometimes meiosis doesn’t quite meios).

I think the influence on these pretty hoers by another media property is undeniable so I rolled with it.

A Nimbval and a Grimass appear in Chapter 4 of my fanfic, Gods and Demons.