No Game No Life, Vol. 8 (light novel)

Just as the end of Sora and Shiro´s dice game against the Old Deus approaches, they are faced with completing Jibril´s task--a strategic simulation game set in a reproduction of the ancient Great War, before everything changed. As the leaders of the weakest race, the Immanity, the gamer siblings have one objective: ensure that in this version of the Great War, no one dies.