Mario Cardoza was a professional killer. He was one of the most wanted criminals in five countries. According to Lucy Becker, he had killed 200 to 300 people, and several Immortals. In 1952 Warsaw, Cardoza hired Amanda to steal a vase for him from a conference room, replacing it with a duplicate. He, however, was not interested in the vase, but he had placed a bomb in the duplicate without informing Amanda. For Amanda it was an easy job to exchange the vases. As he had planned, the bomb exploded during a conference.
Cardoza was an avid cook, he owned an restaurant called "Coco Lezzone" on Fourth Street. In 1996, he received an award for his cooking skills.
To be able to pursue his main profession undisturbed, however, he had taken great care to avoid being photographed, and destroyed any photographs that existed of him, except one. The last one was in the hands of an old Navajo, a former code talker and intelligence operative, who had taken it in 1952.
In 1998, the Navajo, now an old man, met Cardoza and began to ask questions. Cardoza had the man killed, but it was witnessed by Nick Wolfe and Amanda, who were then after him. Cardoza finally staged his own death in order to go underground, and let himself be shot in public. When he revived, he returned to his restaurant. There he killed the only one of his henchman who knew about his Immortality. Before he could run, however, Amanda confronted him. In an parking garage they had their final fight. Cardoza was very good, but in the end he was defeated. Amanda took his head and Quickening.