Eva Kant (Miriam Leone) is the accomplice to legendary thief Diabolik in 2021 action crime film Diabolik.
Legendary thief Diabolik plans his next heist: stealing a valuable diamond from heiress Eva Kant, who is dating the deputy minister of justice, Giorgio Caron. Using one of his trademark masks to impersonate his nemesis, Inspector Ginko, Diabolik tricks Eva into revealing which hotel she will be staying at. He makes another mask to pose as one of the wait staff assigned to her room, and quickly locates the hidden safe where the diamond is kept. However, upon seeing Eva, he becomes infatuated with her.
Diabolik sneaks into Eva's room to steal the diamond, but Eva walks in on him, and he has no choice but to hold her at knifepoint. Eva calmly reveals that she doesn't have the diamond, having already sold it to a dealer in South Africa, and Diabolik leaves. The next day, he returns and unmasks himself in front of Eva; disgusted by the lecherous Giorgio, she starts an affair with him. Unbeknownst to Diabolik, his girlfriend Elisabeth, from whom he has hidden the truth about who he really is, accidentally uncovers his secret hideout. Ginko is notified and arranges a sting operation, resulting in Diabolik's arrest.
At trial, Diabolik is convicted and sentenced to be beheaded via guillotine. When Eva learns of his fate, she has Giorgio use his influence to arrange a clandestine meeting in Diabolik's cell. Once the guards leave, Eva incapacitates Giorgio and Diabolik questions him to learn where he is keeping a file containing information as to Eva's unsavory past, which he had been using to blackmail her. He then dons a mask of Giorgio's face and puts on his clothes to escape, while a drugged Giorgio is fitted with a Diabolik mask and executed in his place. Ginko figures out the deception in time to stop Diabolik from retrieving the file; one of his officers finds it instead.
Needing money to flee the country, Diabolik targets a bank holding expensive jewelry and watches. He has Eva impersonate a rich widow named Ms. Morel to rent a vault. This enables her to learn about the bank's security features so Diabolik can figure out how to bypass them by flooding the bank and using diving equipment to steal the jewels and watches. Ginko, using his knowledge of Diabolik's modus operandi, is able to determine his escape route and briefly holds him at gunpoint before Eva distracts him and he is overpowered by Diabolik. The two make their getaway on a motorboat while Ginko can only watch in defeat.
Sometime later, Diabolik and Eva are on a yacht. To cement their new partnership, he presents her with a gift: the diamond.