Taint

Target a Being or Creature card on the
opponent's field. All of its activated abilities have
its costs changed to Black.
You may play this card for {b}{b}{b} to target a
Being, Creature, or equipped Artifact card on the opponent's field and change its color and all its activated abilities' costs to Black.
"Corrupt the crystal. Teach it pain. Teach it your
anger." - Sith text on bleeding Kyber Crystals