Van Argiano

Van Argiano is the head scientist studying chiropterans for Cinq Flèches.

In Okinawa
He first appears in Okinawa, where two 'mice' (his nickname for the lab-created chiropterans) were spotted. They use a special frequency to detect 'mice'. That frequency affects Riku,  who is somehow also able to hear it.

In Vietnam
Van was in charge of the development of Delta 67, working under Solomon and  with his assistant  Archer. He and his subordinates distribute cinq fleches products to children to develop D-67 syndrome in them. Then they kidnap them to imprison those children as raw materials for Delta project. Kai and Riku happened to be in there at the same time they were conducting delta raw experiments. Riku catches Van's eyes for being able to hear the special frequency although he never consumed cinq fleches product. So, Van orders to kidnap him along with Mui. Later, Saya and Red Shield arrived at their raw experiment base, which was Karl's mansion and Van had to flee as well as Solomon in a chopper with Diva's container.

Breaking Red Shield
Van is an ex-student of Collins and uses this contact to bring his ex-teacher on his side. He convinces the professor to join cinq fleches where the achievements won't have to be concealed like they have to within Red Shield. With Collins convinced, he baits out Julia who happens to have discovered the mystery science behind chiropteran specialty. Succeeding to bring out the two most important persons from Red Shield and getting info on their HQ which he later conveys to Amshel, Van plays an instrumental role in breaking Red Shield.

Promotion
Despite knowing their true nature and plans, Van sided with the chiropterans and aided them in their efforts to spread chiropterans around the world. After Solomon defected from the group, Amshel a ppoints Van as the head of the Cinq Flèches American branch.

At The Metropolitan Opera & Kidnapping Mao
However, he was betrayed at the Metropolitan Opera House and was not told of the plans to turn people there into chiropterans. Fortunately, Van escapes unharmed after using the opera house's emergency exit. After that, Van kidnaps Mao and kills Akihiro with Aston's  SIG Pro SP2022 pistol, then takes Mao to the Brooklyn Bridge, which he will blow up along with Mao unless the Red Shield pays a ransom of ten million dollars. Kai goes off to save Mao, but Van challenges him to a French sword duel to the death before saving her.

The Final Duel & Death
After Van stabs Kai in the chest and cuts off his left forearm, Kai manages to slash Van's entire upper body, causing him to bleed to near death. When Van tried to stab Kai in the chest again, his sword gets stuck to the metal, which prompted Kai to cut his sword in half, leaving Van in shock. After Van tried to cut off Kai's right arm, he knocks Van's sword off his path. Kai stabs him in the chest, causing Van to drop his sword as he and the sword fall into the East River bellow. Van survived the fall and opened one last sour ball, but it he chokes on it, thus killing him.