Final answer:
The trait that signifies a personality flaw leading to a character's downfall in tragedy is called hamartia, as seen in Creon's pride in 'Antigone' and Oedipus's arrogance in 'Oedipus Rex'. This tragic flaw, often hubris, is integral to the structure of a Greek tragedy, where the tragic hero experiences anagnorisis and a subsequent scene of suffering.
Step-by-step explanation:
The trait of tragedy where a main character possesses a specific personality trait that ultimately leads to their downfall is referred to as hamartia. This term, coined by Aristotle, describes the "fatal flaw" that brings about the tragic hero's demise. In Greek tragedies, such as in Sophocles' Antigone, we witness Creon's hamartia as his excessive pride, or hubris, which is a common form of hamartia in Ancient Greek literature. Characters like Oedipus from Oedipus Rex are also classic examples, where Oedipus' arrogance is his tragic flaw that triggers his suffering, yet the audience empathizes with him due to his good intentions.
The construction of a tragedy, according to Aristotle, should incite pity and fear in the audience, hence the character between the extremes of moral spectrum, but whose downfall is not due to depravity, but some error or frailty, is the ideal tragic hero. The tragic hero experiences not just hamartia, but also anagnorisis, a moment of recognition of the error, which often leads to a scene of suffering, wherein the consequences of the tragic flaw are felt not only by the hero but the surrounding characters as well.