Complex sentence: Her monsters tend to sap more sanity from the player than the monsters from other alignments'and therefore if Pious picks Xel'lotath the game tends to get creepier faster as the player loses more sanity than they gain.
Split into simpler sentences: Her monsters tend to sap more sanity from the player than the monsters from other alignments. Therefore if Pious picks Xel'lotath the game tends to get creepier faster as the player loses more sanity than they gain.