Complex sentence: While riding the elevator down into the Abyss, Simon encounters a creature that used to be another PATHOS-2 staff member called Ross, which is happy that Simon had made it this far and tells him that he will make "preparations" before disappearing.
Split into simpler sentences: While riding the elevator down into the Abyss, Simon encounters a creature that used to be another PATHOS-2 staff member named Ross. "Ross" is happy that Simon has made it this far and tells him that he will make "preparations" before disappearing.