Similar to Hidden Fatess Rowlet, there is an exception to this
Understanding how mana abilities work is very important when using these cards, as many of the best colorless cards MTG players can get are mana rocks
Likewise, Bea is the gym leader of the 4th gym in Pokemon Sword
I won't list them all but some examples: "Hard" counters : Mana Drain, Cancel, Rewind, Last Word, Cryptic Command, "Soft" counters (counter unless): Rune Snag, Mana Leak, Mana Tithe Counter abilities: Stifle, Voidslime, Disallow, Tale's End Restricted targets: Nix, Remove Soul, Negate, Red Elemental Blast Other ways to remove from the stack: Summary Dismissal, Mindbreak Trap, Spell Queller, Venser, Shaper Savant
With enough such access, you can even build around Treasure in a way that helps prevent the opposite evil: mana flooding