Dirtiest Dan

You attempt to interrupt a creature in the process of casting a spell by challenging them on who is the Dirtiest Dan. The target must make a Charisma saving throw. On a successful save, this spell has no effect and you cannot cast this spell again until you have taken a long rest. On a failed save, if the creature is casting a spell of 6th level or lower, its spell fails and has no effect. It will instead spend the rest of its turn attempting to the best of its ability to prove it is the dirtiest of all Dans. This spell has no effect on undead, constructs, and Dirty Dan. He is already the Dirtiest Dan.