Dear Captain Renard,
(Rather than Captain Athos, who pardons me in advance for the use of his first name, as that's how I distinguish you both!)
I had the pleasure of witnessing your duel the other day and I was most impressed with your form. You both fought with great distinction and honor and I was pleased to be able to bear witness to it.
I think this is a wonderful idea to be sharing your knowledge of sword mastery with others. My compliments to you, sir. As ever,
Yours humbly,
Captain Faye La Roux