Complex sentence: Simon and Maia are currently alive, on the boat when Valentine arrives and throws silver dust on Maia, hurting her and then tells Simon he is going to kill him, and if he had any last words.
Split into simpler sentences: Simon and Maia are currently alive on the boat when Valentine arrives and throws silver dust on Maia, hurting her. He then tells Simon he is going to kill him, and if he has any last words.