Seriously I gotta know
A military group based on Batman sent a bunch of military drones around the city to kill innocent people. Tim Drake couldn’t shut them off but he could change their target so he changed it to himself. He destroyed the whole first wave of them because he is awesome but was overtaken by the second wave. Hopefully this is what you were referring to, it happened early in the rebirth reboot of detective comics. Very good read with a great surprise about Tim at the end.