Blade x Bullet is the latest in the Soleil series (search my blog, I played all but the most recent previous entry in a marathon a few months ago).  This series is based off of a series of parallel worlds that proceeded from the end of Ragnarok, the last battle of the Norse gods.  Some of those worlds are similar to our own, others are of a greater technology, and others are worlds of magic.  The world in this VN is in the midst of its own apocalypse, mechanical monsters from the sky invulnerable to weapons of high technology massacring humanity.  The only hope for humanity are the Valkyries, powerful spirit weapons created using the corpse of a human woman (or a living human woman), a weapon that has tasted the blood of thousands or a divine artifact, and a powerful spirit.

By the time the story begins, the failure of the Valkyries is apparent, and the survivors amongst them have been gathered at a castle to compete to gain the power of Odin, in order to birth a new world... after fighting one another to gain the runes that lie at their cores.  The protagonist, Yagi Mutsuki, a human warrior from Japan known as the 'ally-killer hero' for the fact that all who accompanied him into battle died but he killed more monsters than anyone else, dies and is resurrected by the Norse Goddess of the Dead, Hel, and given the mission to destroy humanity's hope for the future, accompanied by the Valkyrie Reiganlief.  

Mutsuki is... more than a little crazy, probably because he is the holder of the soul of Loki (this isn't a spoiler, since they say it from the beginning), with a love of trouble.  He makes his decisions on whether an event is to his tastes or not, rather than by any kind of moral compass.  As a warrior, he is unsurpassed amongst humanity, but he is more self-derisive than you would imagine from that.  He is also heavily under the influence of his Loki side after being partially resurrected from the dead, so his personal darkness is behind a lot of his actions (he basically rapes most of the Valkyries at one point or another, though that seems to be his twisted way of showing affection... not that even he thinks that justifies it). 

This story is heavy on the brutal outcomes, with a general sense of impending doom that is typical of the series.  However, it is so excellently written you almost wouldn't think it was written by the same person as Shin Shirogane.  I honestly loved Mutsuki's plotting to outwit fate, and the ending is pretty exhilarating... and fitting for one brought about by a guy who tempers Loki's chaotic nature with more human emotions.  The game is a bit short, as it is a kinetic novel with a set ending.  However, that didn't take away from my enjoyment, as I felt they developed the characters more skillfully in this one than in the last few games. 

Overall, if you don't mind the excessively dark themes and some tentacle rape, this is a fun game to play... though I have to say that Mutsuki is the most atypical protagonist in the series so far, being as far from heroism as it is possible to be.

Edit: I should make a correction... he doesn't actually rape Fenrir, Reigenleif, Yorm, Brunhilde, or Grimgelde... but he is so S that it feels like it.  I actually think the only time it was actually rape was with Ottlinde... lol