Complex sentence: After the ceremony, he stays with them as he is on summer vacation, and has recurring nightmares.見知らぬフローリングの床にうずくまり 、 and holds down a strong homicidal impulse surfacing from deep within himself.
Split into simpler sentences: After the ceremony, as he is on summer vacation, he stays with them. He experiences recurring nightmares and must hold down a strong homicidal impulse surfacing from deep within himself.