Complex sentence: Later when Chuck Russell (Producer) got the chance to direct 1994's the Mask, he was finally able to use Jim Carrey, transforming the Mask from a "very dark horror film" to a comedy.
Split into simpler sentences: Later when Chuck Russell (Producer) got the chance to direct 1994's the Mask, he was finally able to use Jim Carrey. This transformed the Mask from a "very dark Horror film" to a comedy.