[wally-balls]

I'm not sure that they want to be referring to Rosselli as the "protagonist" of the story. Unless I'm wrong, and I often am, the protagonist is, in literary usage, the hero

[beyond the sea]

1. The main character in a drama or other literary work.

2. In ancient Greek drama, the first actor to engage in dialogue with the chorus, in later dramas playing the main character and some minor characters as well.

3. A leading or principal figure, the leader of a cause; a champion.

[Savage Beast]

The protagonist is the main or most important character. It need not be a hero. It comes from the Greek word protagônistçs, from agônistes, competitor or contestant, from agôn, “contest” (the word agony comes from the same source). In classical Greek drama, the protagonist was the first character to interact with the chorus. In modern usage, there may be multiple protagonists, meaning multiple main characters, but they need not be heroic; they can be anti-heroes or whatever.