There’s a wide list of taunts available, but there’s always room for more. Here’s a few I have; some are courtesy of a king jerkass from Starcraft, Alarak.
“At least your failure was spectacular!”
“The IDEA is to be better than your enemy, you know.”
“Your attempts at survival are… insulting.”
“Did I give you permission to live? I didn’t think so.”
“Need me to give you a lift back to the starport?”
“I doubt you’ll learn from this.”
“You call THAT fighting for your life?”
“Mind if I interrupt?”
“Is that your best?”
“That was pathetic!”
“Always gotta be the hard way.”
“You die too easily.”
“If you want me to shoot you less, blow up sooner.”
I’ll add more if I think of them.