Sir Pentious has so many eyes because in life he was always a watcher, a spectator of his own life. He preferred watching people and pretend to be in their lives and their friend, instead of going out and actually engage with them.
And so, his watching was his doom. He saw the murders, and didn't do anything. He was cursed with so many eyes, as a reminder of his sin.
Apathy and cowardice were his downfall.
And yet... in Hell, he tends to do the opposite.
In fear of being a bystander once again, he's constantly throwing himself into action, very often on a whim, instead of actually going with a plan.
His whim? Fitting in, doing like the others, AKA being mean, ruthless and destructive.
But that's not who he is. He's soft-hearted, easy to fluster and even rather shy. And yet in Hell he's (perhaps subcontiously) constantly forcing himself to be more bombastic and impulsive so to avoid making those same mistakes.
He redeemed himself because he used that whim to not fall into his past mistakes, to do something that actually truly mattered to him: protecting his friends, no matter what could happen to him.
And he did it with newfound courage: still scared, but willing to give his life for the ones he cared about. And he went out not like a diabolical mastermind, but like the clumsy yet golden hearted man he's always has been.
