Re: DC's turn toward the dark
Sorry, no. It's been done. 8 issues story arc across all four Superman titles, if I recall, "Ending the Fight."
Manchester Black made Superman think he'd killed Lois. He was trying to get Superman to kill him, in an attempt to prove Superman isn't as pure as everyone thought. Superman refused to kill Black, wanted to but refused to, because Lois wouldn't have wanted him to, and he wanted to preserve his memory of Lois, and be what she wanted him to be.
Black did commit suicide. Blew his brains out using his TK. Which led to the Justice League Elite story with Black trying to take over his sister.