As Oz strangles Victor to death, he explains that he can’t have any weaknesses. His regard for Vic is a weak spot that could be exploited by other enemies in the future. So he eliminates that chance by killing Vic himself. “He really loses his humanity by the end,” LeFranc said, “or any inkling that he had of it.”

"The Penguin" finale finds Colin Farrell's gangster ascending to power in Gotham City and losing "any semblance of decency" he had left, Farrell says.