What words refer to acting harshly?

act harshly, abrasive, abrupt, acrid, acrimonious, brute, bully, caustic, cruel, cruelty, demanding, exacting, forceful, grate, grim, hard, harsh, martial law, pugnacious, rigid, rough, severe, sharp, stern, stiff, stinging, strict, stringent, tough, unfavorable, unfeeling, ungentle, violent