Omerta the Silencer has two origins as he was rebooted after the Batman/Huntress: Cry for Blood
Pre-Cry For Blood
Donald Campbell was the Consiglieri for the Bertinelli family. He was frustrated because Guido Bertinelli
never made him a family insider. As Omerta the Silencer he was employed by Stefan Mandragora
to kill Guido and his family. He also wrote his name onthe wall in the victims blood. Unknown to him Helena Bertinelli
did not die and unknown to her was his identity. After the massacre she got her father's money from Donald himself and when she left he tried to kill her again as Omerta.
Not knowing Donald was Omerta she went into hiding with the help of her old bodyguard Tony Angelo
. While hiding he trained Helena who wanted revenge for her families murders. She went back to New York City
to find Omerta as the Huntress, and she had a couple run-ins with him, but he was always able to escape.
He eventually tries to fool her by having the newspaper say that her father was actually alive. When Helna gets to the office Omerta shoots at her again but this time she is able to escape. It is after this event that she realizes Omerta and Donald were one and the same, she then goes back at night to find him. When she tries to get the drop on him she fails and he gets the drop on her instead, captured he plans to rape her but Mandragora
stops him. They kidnaped Huntress and take her to a secret safe that belonged to her father. They use Huntress blood to open the safe and afterwords Mandragora asks her to be his leader in New York City. Of course she refuses to work with someone who killed her father so Madragora shoot and kills Omerta, killing him to prove his serious intention. Also obvious Huntress still refuses to join Mandragora and she even kills Mandragora herself makeing Omerta's death completely pointless. A poetic end for the man who murdered at least around a hundred people.
Post-Cry For Blood
He is again the Killer ordered by Mandagora but this time Santo Cassamento is the mastermind wanting to erase Franco
and Helena Bertinelli
(of which he is the true biological father). This time however, he makes a mistake. Helena's mother was the one intended to be left alive, but he accidentally kept Helena alive instead.