Bubble is one of the three Aspects of Rhisis. He, like Iblis and Shade, was created when Rhisis drew energies from three aspects of herself. Bubble, who bears the official title of "God of Joy and Purity" represents Light and Color and is most commonly associated with Flaris. He struck out at the Masquerpets with such might that he split Madrigal into 3 main continents and scattered the Masquerpets throughout them. It is suspected that he assisted the Heroes in the Hero and/or Clockworks wars. He looks something like a cross between Santa and a court jester.
Bubble himself does not exist ingame, but models, textures and animations exist for him, so GMs can choose to appear as him if they want to.