@
Ifrittuccia tate yuusha is more mild than this... and mind you, tate's MC is not actually cruel, ruthless, and wicked as he still has some considerations for his fellow heroes friend and even to malty and the king...
for now, kaifuku is the only one that very similar to this manga... the differences are the MC's personality... up until now, nidoyuusha MC is depicted as a more straight and less wicked in his revenge, also more brutal, cruel, and ruthless (as far as the manga goes up until now)... while kaifuku MC's is depicted as a more sly, wicked, and a bit manipulative...
tate yuusha can NOT even be compared with those two... also tate's objective about revenge is already fulfilled (and now slowly turning into a normal adventure fantasy manga), those two nidoyuusha and kaifuku are pure about revenge (and probably will end after its objectives are fulfilled)...
the only element they shared is revenge... if you're talking about similarity, nidoyuu and kaifuku are the most similar than tate...