Final answer:
The missing word is 'characterization', which refers to the act of accurately representing and exposing the flaws of a person's opponent.
Step-by-step explanation:
The missing word in the sentence is 'characterization'.
The student is describing a person who is an eloquent speaker and has the ability to captivate the crowd with wit. The missing word should describe the person's ability to understand and expose the flaws or weaknesses of their opponent. 'Characterization' refers to the act of representing or describing a character's traits. In this context, it means the person has the skill of accurately representing and exposing the flaws of their opponent, which proves fatal to them.