How does Byron's main character in "Manfred" represent a Byronic hero?
The Byronic hero displays the extremes of human nature, and Manfred certainly illustrates this. His whole life is one of extremes. For one thing, he feels himself completely estranged from his surroundings, existing at the extremes. If anything, he's more of a supernatural spirit than a human being, showing a haughty contempt for society, religion, even the natural world itself. He desperately wants to forget the incestuous relationship with his sister; but he cannot do so. Instead, he seeks oblivion. Despite his appearance as a supernatural force from the beyond, he's still fully human; he has a moral sense and knows what he's done is evil. At the same time, however, he cannot accept responsibility for his actions. So he stands alone, as almost a being outside of time, trying to relate his disreputable past to the present and also on into the future.
Some measure of redemption is achieved by the end, but, importantly, on Manfred's own terms. He still remains the Byronic hero. He recognizes that there is still some good in himself as there is in the world as a whole, but this realization has only come about as a result of systematic rebellion against the temporal world and its conventions. He remains both sublime and self-absorbed, but now possessed with fresh insights into his own personality and the natural world that swirls about him in a never-ending flux.
A Byronic hero is a tortured soul who is often reckless or violent, always brooding and introspective, and alienated from the rest of humanity. He isolates himself and suffers in solitude as a dark, misunderstood figure. Heathcliff in Wuthering Heights is a well-known example of the Byronic hero.
Manfred stands as well as as a fine example of the Byronic hero: he is tortured by the conviction that he destroyed Astarte, the woman he loved (though we are not given any details); he wanders alone in the Alps; he is on the brink of suicide when the Chamois Hunter saves him from that fate; he has to defend himself to the Chamois Hunter as not insane; and he questions and rebels against both the authority and "heaven or hell" doctrine of the Christian church. He is determined to face both life and death on his own terms and dies having refused to capitulate to institutionalized religion. He lives and dies as an individual who asserts his own will by refusing to conform to social norms.
There are many similarities between the protagonist in Byron's work and the Byronic Hero. The most dominant one is that Manfred, like the Byronic Hero, is someone cast apart from society. Simply put, he is "different." The Byronic Hero is one who is distinct from the social order. He is solitary and one in whom others stand in awe. Manfred is certainly this. The question upon which Manfred undertakes is one whose motivation is not entirely known. We understand that some internal demons animate and drive him, yet we do not fully understand what this exactly is, consistent with the Byronic Hero. Manfred is extremely adroit and skilled, another trait that is part of the archetype. Finally, when Manfred is able to accept his overall fate, the reader is able to see that Manfred is an overall decent human being, something that the Byronic Hero receives at the very end of the narrative.