Well heck, we might as well try and design one then, let’s make it a gem creator:
Name - Roy G Biv
Type - Divine Human Mystic (because why not)
Colors - all of them, like the Hero Prismatic Orb
Spell - Kaleidoscope (18 mana): Create 9 gems of a chosen type. (Not sure if we need to add another ability such as gain extra turn if 13 or more of that color is present)
Mythic Trait - Prismatic Link: Gain bonus Mana from Gem Matches. (Or 4-5 gem matches if that’s too powerful) Have to phrase it that we’ll know that red matches will only give bonus red mana, etc
So this begs the question: how the heck would we trait an all-color Mythic? Probably use a certain number of all of the mono-color Arcanes I presume.