My training has proved that I can't beat a stable boy with my left hand
I pushed a boy out a tower window, crippled him for life for Cersei. I strangled my cousin with my own hands just to get back to Cersei. I would have murdered every man, woman and child in Riverrun for Cersei.
Every last sparrow will die before Margaery Tyrell walks down that street
Any decent swordsman knows how to use both hands