 If you liked
Tate no Yuusha no Nariagari
|
 ...then you might like
Kuro no Maou
|
Both of manga show the grim reality of how world works and how much sacrifices needed to become the greatest of you.
Both of the story indeed about vengeance but instead showing unnecessary vengeance, their path of heroic story was justifiable in fact they're deserve more recognizing from other fantasy tropes that filled nothing but nonsense.
Trust me, if you're like me who looking the proper fantasy with proper path of world then both of them are your strong suit