I think the only way I could watch this, what with far too many of the main characters dying all over the place, is by distancing myself to the point where I don't care about any of the characters. I think that would mean I wouldn't like it much, though.

Gundam 00 pulled the whole "let's kill the main characters off" on me without me knowing beforehand and the emotional punch from that was so bad that I haven't been able to even watch the last episode of the first season or go one beyond that. So... I'll say that I'm very, very grateful that you pointed out that Guren kills off the people the viewer likes/loves too. :D Now I know that I shouldn't watch it. I have fic to write so I can't deal with triggery stuff and depression right now.

I hope you find the slashy fic you need! :)