This may seem like a strange question, but curiosity got the better of me. When googling it, I couldn't find an answer so I've turned to the wiki for answers.
Which DC comic has the most deaths?
One I've found is https://dc.fandom.com/wiki/Countdown:_Arena_Vol_1_4 while looking at it for another discussion, which has 10 deaths. Let's use that as a starting point.