Cursed for a lifetime of indifference, his punishment was both complex and seemingly cruel; stripped of the essence of his soul and damned to ferry those destined to leave the mortal to their destination, but never reach his own.
Stripped of his indifference as a means of punishment (in taking the cornerstone of his personality, the very essence of the man was destroyed), he became self-serving, finding value in his damnation in a way that was never anticipated. Rather than wallowing in his prison, he excelled, finding a great joy from what was intended to be his Hell.
He appears to have compassion, sympathy and understanding, but beyond all he aims to please himself. He collects trinkets and lives very much for the moment, as he is constantly at risk of being pulled back into his limbo when wandering the mortal world; summoned by his everlasting duty to the dead.
After a life of chronic indifference, he plunged into the River Between Realms upon death, but rather than drifting towards the afterlife, he found the current stilled. In life, he held no care for heaven and no fear of hell, in so doing slighting both.
His punishment had many levels.
He was stripped of his indifference, to take away his innermost self and force him to acknowledge and feel in his new existence. He was granted the knowledge of his punishment, but not of his crime; he knows only that he deserves exactly what he now has. His unlife is eternal, constantly ferrying souls along the River to a destination that he can never reach, coming scant inches away from a greater truth but never able to realise it himself. He is the Boatman; he transports souls forever, but is forever below them. He never gets to arrive, always returning for the next passenger before he has chance to pass on himself.
However, rather than seeing his existence as a curse, he could see nothing better than the life he had been granted by his former deeds. He lives for the moment and creates luxury for himself, easing the journey for those willing to pay him with some small trinket. When the whole of time is but a river, and he is the boatman, a small trinket can become ages old and worth the world in moments.