Complex sentence: Staggering out through the debris, he takes with him the world-famous painting of "The Goldfinch", which will serve as a singular source of hope as he descends into a world of crime.
Split into simpler sentences: Staggering out through the debris, he takes with him the world-famous painting of "The Goldfinch". This unique object of beauty sustains him as he descends into a world of crime.