Complex sentence: Despite exuberating charm and paternal warmth when interacting with the public and his "children", he is, in reality, an utterly ruthless narcissist, who has no concern for the physical and emotional well-being of those who serve him.
Split into simpler sentences: Despite exuberating charm and paternal warmth when interacting with the public and his "children", he is rather deranged and cold-hearted in reality. He is completely single-minded in pursuit of his goals, and shows no concern for the physical and emotional well-being of those who serve him.