|Occupations||Assassin; Mermaid leader|
|First Appearance||Chapter 4|
Darkness Isaac is the leader of Mermaid and the second in command of Gabriella. Even though Don Salieri is technically the leader of Gabriella, Isaac is the one in charge and is the one who commands the respect of the seven heads of Gabriella and the respect of the Mermaids. They see him as their real leader and only follow Don Salieri because of Issac's loyalty to him.
Isaac is tall and muscular and was once one of the many immigrants that had come to Cicero City.
He has white-blond hair that is in a buzz cut and dark eyes.
He is always seen with a long, white coat with vest and dress pants underneath, he also always has his sword.
Isaac is extremely loyal to Gabriella and his boss Don Salieri. he is a ruthless fighter and is one of the most feared and respected members being the second in command. He seems the genuinely care about everyone in his command.
He is extremely calm and slow to anger.
All of the members of Mermaid became members because he defeated them and told them to live for something more, this shows that he can be very good at understanding people.
Weapons and AbilitiesEdit
Isaac uses a long sword, it is a large two handed weapon, though he uses it occasionally with only one hand. His sword is double edged and has a cross guard, on the blade there is a design that comes down the blade in a "V" and then extends in a line for part of the length of the blade. He carries his sword in a dark sheath on his right hip, under his coat.
Blade of Darkness/ Brand Nero: He uses a technique called 'Blade of Darkness' or 'Brand Nero' were he keeps a perfectly straight stance at a safe distance from his opponent, the moment he understands what move his opponent is going to use, he moves into the opponents blind spot. While he is behind his opponent he has a posture where he can adjust his center of gravity in any direction. An expert in stealth can even disappear from his opponent's field of vision for a moment, using this technique. But to use this technique's full potential he must have kill all fear and have the strength of will to face death itself.
This technique is extremely powerful, so powerful that Isaac was able to get past 'Shinigami' Roxy's attacks.
Bravery: Isaac has great courage, and is able to stay calm in any situation.
Strength: Isaac is incredibly strong, being able to swing his long sword very quickly and hard. He is also able to keep up with Shinigami Roxy's attacks.
To be able to use his Brand Nero technique he must be very fast. He has to let his opponent attack first, dodge that attack and then get behind them, he is so skilled that he seems to disappear.