Shitiest route, not only Shiro left alone and hearth-broken but new graal will spawn so all shit will repeat itself, Sakura's story is darkest but most satisfying.
Chapters 1-15 was great but after suddenly drawing worsen a lot, the story lost its ways too. 1-15 is the reason why this manga has a high rating, after that it becomes average harem crap.
Skull King killed that 4 fingers for sure, his girl was sacrificed so he lost control and become full berserk who can kill multiple chosen with ease, yet his life-force ended before he killed Void.