You have already been attacked once; and I don't want another corpse on my hands.
When monsters battle on the field, they can attack once, defend, or use a special ability.
I have an 18-year-old child who was once attacked.
I was once attacked by 18 blokes and put nine in hospital.
They had attacked once and surely they would come again.
He was once attacked by one of his lions.
He is a stranger in our land and has already been attacked once.
A group of gunmen once attacked a colleague, who spent six weeks in the hospital with a broken shoulder.
If they once attack us, then we will, of course, attack, in reply.
He received several death threats from gamblers who had bet against him, and was attacked once.