Rionya, Fire Dancer Everything I said about Orthion, Hero of Lavabrink and Delina, Wild Mage is easily applicable to Rionya, Fire Dancer as well
This legendary land adds an upkeep cost of one mana to all creatures , on top of any existing upkeep costs, or else they are destroyed
With an Ability Patch and a helping of Max Soup from the Isle of Armor, you can bring out the Hidden Ability of the first partner Pokmon you chose at the beginning of Pokmon Sword or Pokmon Shield and give it the capability to Gigantamax as well
Sadly, the ability to get non-Forests to fix your color concerns likely will never come up since there are so many good colorless lands available for mono-color decks to take advantage of
This power is enough to eliminate any card in the game, including those saturating the meta, such as Darkrai ex and Celebi ex