pokemon tcg brilliant stars booster pack TCG: Sword & Shield 30 cards with special art in the Trainer Gallery subset Pokémon TCG: Sword & Shield-Brilliant

On closer inspection, you can see that the skeleton isn't even a real skeleton, but likely to be an artifact creature of some sort with all the magical runes and/or mechanical circuitry on the skull

You can feed all this mana into generic mana costs, X-spell costs, or, with Chromatic Orrery out, use it to cast whatever you like

Turn it face up any time for its mana cost if its a creature card.) Greater Tanuki Greater Tanuki is a six-cost (four generic and two green) enchantment creature with Trample

The "legend rule" is referenced on these cards directly, or perhaps they create copies that themselves aren't legendary