Symbolism, Imagery, Allegory
When he was a baby, Flamineo grabbed a crucifix that belonged to his father and tore off one of the arms (which was then mended by his parents or perhaps by someone else). Cornelia and Marcello are discussing this event right before Flamineo enters the room and murders Marcello. Dying, Marcello laments:
Oh, mother, now remember what I told
Of breaking of the crucifix! (5.2).
Clearly, this is meant to indicate that Flamineo is a pretty bad guy. It suggests that his views were, straight from birth, those of a mini-Antichrist. In Flamineo's worldview, naked self-interest and hate are the main forces that make people do what they do. He's totally opposed to the Christian concept of selfless love or brotherly love—made perfectly clear by the fact that he just murdered his own brother.