Some existing examples include:
"You fight like a dairy farmer!"
"How appropriate. You fight like a cow."
and
"My enemies fall at my feet when they see me coming!"
"Even before they smell your breath?"
I'm sure we have enough members with cruel and scathing wit to make this work. I'll throw down the gauntlet first. Retort if you dare!

I've seen spoons wielded more dangerously than your sword!