 If you liked
Houseki no Kuni
|
 ...then you might like
NieR:Automata Ver1.1a
|
Both series depict a never-ending war between two different lifeforms with ties to humanity over the course of hundreds if not thousands of years.
The protagonists also both undergo severe mental deterioration after a traumatic event causes them to change forever.
Both series have a strong focus on themes of existentialism and purpose. If you love Nier you'll also love Land of the Lustrous (and vice versa).