Who or whom in this instance?

The sentence: "While this speech follows a classical tradition of ending a drama with the victor, who has proven to be less than ideal, speaking over the dead body of the defeated, Antony’s speech depicts the essence of the ideal Roman, and Elizabethan, when he refers to the pure honesty and honor that Brutus held steadfastly."
Using who sounds right but since the Victor is the noun it refers back to and Victor is not the subject in the sentence I guess it should be whom? My prof hasn't marked it wrong but it doesn't feel quite right