I have a few ideas that I believe could be quite good but I need a decent second opinion. Don't go easy, be as critical as possible. A modern/fantasy action story about a very non-stereotypical version of apocalypses' four horseman. Hell is overflowing and Death (very cynical and dark humoured) must bring together the rest of the horsemen: War (a female, leather wearing, badass.) ; Famine (an obese, stay-at-home, layabout) and Pestilence (a sharp suit wearing man with OCD) and decide whether to side with the demons of Hell or the Angels of Heaven. Death will also be accompanied by a 'mortal' man with suicidal tendencies who changes his mind throughout the story.
This actually sounds very familiar. At least your version of the horsemen. And now that I think about it, the rest sounds rather reminiscent of It's a Wonderful life. That said, everything reminds me of something.
Got it! Took me a while as my memory sucks. Your War? She could have been lifted straight out of Good Omens by Neil Gaiman and Terry Pratchett. They refer to their Horsemen as, 'The Horsepersons of the Apocalypse.' If you haven't read it, you should check out War's character page from the Good Omens Lexicon.
Giving my 2 cents: I'd so read about a female, sharp-dressing, OCD Pestilence! The badass, leather-wearing War is okay I guess, but it seems to me as though writers are prone to giving a female the "badass" role to get their quotas straight, which way too often ends up in 2-dimensional, trigger-happy "dude-with-boobs" syndrome.
For a moment it looked like you wanted to write about war through the eyes of horses. Good idea, but not as original as yours.