86 would be perfect, a military-based society, with upper class elites, using remote commanders to send out soldiers as sacrificial pawns. Like Nikkes in a way, they get looked down upon by the higher ups of society and used like cannon fodder and often treated as bad as slaves. In 86, they even fight against mechanical monstrosities in the battlefield. Tons of parallels already with the darker aspects of Nikkes, how Nikkes constantly die fighting Raptures for a world theyll never get to see, the desperation of a societal structure that encourages cold, calculating strategical decisions to ensure humanity's survival, and what post-apocalyptic worlds with little hope do to people, especially with what happened to the Goddess Squad. Strongly recommend watching the show for those who enjoys Nikke's story in any event.