First Appearance: Alpha Flight #108 (May 1992).
Appearances: Alpha Flight #108.
Years Active: Centuries ago to the present.

As always, I'm indebted to Ronald Byrd for information. He pointed out this character, so it's only fair of me to include his words here:

Seen only in Alpha Flight #108, Omerta, we are told, has an extended back story.  It is noted that "as his ancestors have before him---this man's religious order dictates he observes a strict vow of silence in his defense of the people of Italy."  Although he is a master of unarmed combat, whether or not Omerta's physical prowess reaches the level of superhuman is unclear, but when the villainous Brain Drain manipulates various international super-heroes into battling Alpha Flight, Omerta is capable of holding his own against the super-powered Weapon Omega (nee Wild Child, later Wildheart).  Moreover, "it has been theorized that after centuries of non-verbal communication---Omerta's order has evolved the slightest psionic abilities to read and project marginal thoughts."

So, there we have it, Omerta as the end result of a centuries-long program to fight evil; thus, although no other details are provided, it can be assumed that there have been many other Omertas throughout the centuries.  Oddly enough, Omerta's costume is more or less that of the 1970s Karate Kid without the big yellow collar, plus a lower face mask.