Complex sentence: He possesses "pure empathy" and an overactive imagination, allowing him to mentally recreate the murders he is investigating; however, he also unknowingly suffers from advanced encephalitis, often making it difficult for him to cope with his mental recreations.
Split into simpler sentences: He possesses "pure empathy" and an overactive imagination, allowing him to mentally recreate the murders he is investigating. He also unknowingly suffers from advanced encephalitis, often making it difficult for him to cope with his mental recreations.