Jean didn't actually kill Steven Lang, though. He survived the crash, albeit in a comatose state. Later, his mind/consciousness was used in a Master...
It's not that long-range, I think the best showing of that is her fight with Carol in Captain Marvel (2019). She's terrifying, but acting like a real...
Unlike the Fox X-Men movies, Mystique isn't really a hero or even much of a mutant freedom fighter. She is almost always working for selfish causes....