With all the superhero movies I've seen Dark Phoenix was the first to address the idea of not every hero is good, not just physically but mentally and emotionally. What sets Dark Phoenix from other superhero movies is that the characters aren't just all bad or all good, but they are humans who are different but still human. Jean is the main person who is conflicted with a light and dark side of her, but she isn't alone as Hank, Charles and Erik are this too.
Charles, for example is vain and egoistic. He take pride in the fame and glory, it has blinded him of what's really important. Because of this ego, his moral values are thrown out of the window and left to die. Charles has forgotten about how to be a parent, a brother and a loyal friend. By taking his family for granted, he ultimately failed to save those who matter to him there by failed to save Raven.
His mind set of finally finding peace through the needs of fame feeds his at his ego, thinking that this fame is what they all wanted but ultimately it's only what he wanted. As Raven addresses to Hank:
"It's not our life, Hank. It's his"
- Raven Darkholme
This scene is followed by Charles being with the President at the party instead of being with his family. He would therefore spend time with people he doesn't know then his own family. This separation or contact from them sets his ego to a new level and limits Charles's time he has with them. When Raven dies he realises what he missed and however he never wants to admit that he was wrong.
His overgrown ego has come to a point of being unhealthy for his mind. This excess of an ego had lead him to a dark path as he places his position as leader and as a member of the family in jeopardy. It's his human feeling of vanity that proves that Dark Phoenix is different, it's not just a typical superhero movie but it's more human and realistic in portraying these dark sides of the human psyche and the ideals of what it means to be a human being.