Aura Cosmetics.

[Vel]

How about introducing "Elemental Auras" as a unique cosmetic option for Pokémon in the game? Trainers can obtain special Elemental Aura tokens through in-game achievements, events, or as rare drops. These tokens allow trainers to imbue their Pokémon with a radiant aura representing different elements such as fire, water, electric, grass, and more. The Elemental Auras not only add a visually stunning and dynamic glow to the Pokémon but also subtly change the color palette of their appearance, giving them a distinct elemental theme. It's a fantastic way for trainers to showcase their Pokémon's affinity with a particular element and adds an extra layer of personalization to battles and encounters. Plus, it would be a dazzling sight to see a team of Pokémon each radiating their unique Elemental Aura in a battle! this could also be explored or used as particles instead.

 

[Lahm]

Personally I think these cosmetics ultimately lead to too much visual clutter than gets in the way of gameplay during battles, etc. for very little benefit. An issue that I see all the time in games such as Pixelmon. There's plenty of visual expression that can be made through customizing your character which do not effect the gameplay itself in any negative way.