Yes you can mix colors only if your Leader is multi-colored (e.g., Red/Green, Blue/Yellow)
Chthonian Nightmare Chief: If you thought that we were going to make it through an entire article without talking about a card that does something broken with Dockside Extortionist, you were sorely mistaken
The card allows you to discard a card to tutor for a land or battle, both of which play into the archetype
Prevent that Villainous Wealth or Torment of Hailfire of reaching X = 15, dont allow the voltron player to keep their Rogues Passage and get rid of that Urzas Saga before it can tutor up an artifact
And the sadistic Fusion duelist "Yuri" from the Fusion dimension, who works for the Professor in Duel Academy, turning people into cards
Japan Auctions, making it the most streamlined proxy for Japanese C2C marketplaces