interrupt the clerk and the customer

"Excuse me, ma'am," you interrupt the transaction, pushing the man's credits back into his face. He stammers out a few words, but seems easily pushed around. The clerk, however, is unhappy.

"Who are you? What do you want? Get in line and wait," she turns her attention back towards the man as your focus lashes out and dominates her focus. She is startled, and suddenly realizes you are much more than you seem.

"Wait, don't hurt me, what are you?" she protests as she backs up. The mood in the room shifts. Suddenly, everyone is terrified of you.