In short, he committed war crimes which required putting his daughter up as collateral and have lead to the death of thousands, his marriage has dissolved, causing him to pull a gun on Alanna who emasculates Adam before shooting him, presumably killing Strange in self-defense.
It's egregious. There's one issue left, but King doesn't seem like the kind of writer to apologize for bad decisions, so I imagine this is going to conclude with "Adam Strange sucks."