Character Analysis
Piero doesn't do a ton, besides promising to help Antonio achieve revenge and turning up to fight in the climactic last scene. But it's nice to know who he is, if only to avoid head scratching when he appears at the end of the play after being gone for three acts. He seems genuinely upset by the injustice in the dukedom (1.4.50-60), so maybe he'll lend Antonio a hand going forward.