The success and the longevity of a great novel does not lie entirely in the hands of its hero. Many of my favourite novels come with a surprise gift - the character who is most interesting of all, who is not the main protagonist. This is the character you wonder about later, the character that seems to step outside the story and comment on it, or the one whose dilemma is never really solved by the outcome of the plot. This character may be the one who highlights the theme by negating it.
Mr Bennett is the character around whom the story problem - the Entailment - is centred. Mr Bennett is the one who could have seen the family crisis coming, and who, as the head of the family, had the power to avert it - Lydia's elopement, which threatened to ruin the family. Mr Bennett is the one who allows himself the luxury of standing outside the story and commenting flippantly on it, as if the fate of his family had never hung on the decisions he made. In the end, the family is saved, by good fortune operating through the characters of Lizzie and Darcy - and not by Mr Bennett fulfiling his duty. And yet he says, And so Darcy did everything... I shall offer to pay him tomorrow; he will rant and storm, about his love for you, and there will be an end to the matter. And near the end we have Mr Bennett'e delicious irony in this remark to Lizzie: I admire all my three sons-in-law highly. Wickham, perhaps is my favourite; but I think I shall like your husband quite as well as Jane's.
I find Gollum as a character no simple villain, but heartrending. He is the one who lingers with you for a long time afterwards. He is the one some of us in our most honest moments may be able to relate to. Gollum started out an ordinary human being, but became consumed by his lust for the Ring. Thereafter, it is as if he has given over all his power to the very worst in himself. And yet he is offered redemption, by Frodo. Frodo uses his human name, Smeagol, to try and recall Gollum to a sense of who he once was. He demonstrates trust to Gollum. This indicates Gollum can be redeemed if he chooses. And there are moments when he comes close, moments when we pity him so much, and long for him to be redeemed. Yet Gollum's final choice, to grasp the Ring, brings about his own destruction, and that of the Ring itself.
Mr Tumnus the Fawn is the character I think of first whenever I think of The Lion,the Witch and the Wardrobe. Loveable, pure, innocent, representing the natural world, the first inhabitant of Narnia whom Lucy meets, who offers her hospitality and friendship - yet it is Mr Tumnus who is prevailed upon to spy for the White Witch, and first alerts her to the presence in Narnia of a Daughter of Eve. And Mr Tumnus suffers for it. But ultimately he is redeemed.
So I hope these examples serve to demonstrate how your main character will not carry the full weight of the novel's success. And when your hero stands up to receive the accolades, he can truly say, "I would never have done this without..." and then he can credit his supporting team - and among them, the most interesting character of all.