Harry turned away from the hex and let the spell he'd prepared fizzle away. He knew a stinging hex when he heard one; it's one of the first defensive spells any student learns. Why would Oliver open with something so simple?
Quickly, Harry reconfigured his offense. He wanted to teach Oliver a lesson, not kill the man. He had one murder under his belt and didn't intend to add to that total. With one swipe of his arm, Harry sent out three concussion pulses, meant to feel like a punch to the gut wherever they hit.