I was aware that sonic booms happen when something moves faster than the speed of sound, and found out that Cherenkov radiation is emitted is when something moves faster than light, and then I found out that beings fighting at the speed of light would ignite the atmosphere, so I got curious and asked what would happen to onlookers to a fight happening at the speed of light.
Yeah we’d all die, onlookers and everyone else.
It’s worth pointing out that Cherenkov radiation occurs when something moves faster than light in a medium where light doesn’t travel at c. Nothing can travel faster than light in a vacuum without breaking all physics as we understand it.