Some TMNT stuff really isn't for little kids.
Victor was the leader of the French ninja clan called the Savate Ninja. Originally he was the second-in-command of Fabrice, and was sent on a mission to reclaim a tribute of diamonds being delivered to the Foot Clan. During a battle with Karai, he voiced his unwillingness to pay tribute to the Foot. When Fabrice was imprisoned, Victor became the new leader by default.
During the City Fall story arc the Savate Ninja clan attempted to to steal a shipment of equipment being delivered by Karai and her fellow Foot Clan ninja. The Savate were about to finish of the Foot until a brainwashed Leonardo shows up with more Foot ninja. They dispose of all but one Savate ninja, letting him go free to relay a message to Victor, that the Foot Clan will tolerate no disobedience from the other criminal organizations.
While fighting more of the Foot Clan, a member of the Italian Mafia arrives in a car to take Victor to a meeting of all the crime family bosses, who are meeting to discuss the recent escalating conflict between the Foot Clan and all the other families. The head of the Mafia, Antonio, voices his displeasure at the Savate's violent approach to dealing with the Foot. Victor says they have it handled when Marcello speaks out, causing Victor to slay him, to emphasize his point.
Soon after, Victor sent a severed hand to Oroku Saki, with the word "war" pinned to it.
Victor held a meeting of the Savate shortly thereafter, in which he declared that they had crushed all enemies except the Foot. Just then, a Foot strike team led by Leonardo crashed into the Savate base. Victor was chased down by the Turtle and lost his hand to Shredder, but was allowed to live for the time being.
After being captured, Victor and the rest of his clan are brought to an abandoned theatre where the Shredder is holding his meeting between the various criminal organizations in New York City. During the meeting Shredder decides to make an example of Victor and the Savate Ninjas by decapitating him in front of his audience.