Complex sentence: Just as Neil Gaiman's Sandman was not initially a Vertigo comic, this version of the Demon never became a Vertigo comic, but retained much of the early framework of Hell depicted in earlier issues of Sandman.
Split into simpler sentences: Just as Neil Gaiman's Sandman was not initially a Vertigo comic. This version of the Demon never became a Vertigo comic, but retained much of the early framework of Hell depicted in earlier issues of Sandman.