The consept of golem hearts was very good and unique it seems the ending was rushed after the series probably got canceled by the publishers the author was likely forced to wrap up the story within a few chapters but at that point i understand just getting it over with and moving on if it had gotten a chance to go further it could have been very good although generic in many ways so maybe it having almost nothing diserning it from other more popular and overall better writen battle manga was what caused it to get canceled by the publishers it was trying tocompete with mainstream battle manga without much if any twists on the tropes asociated with the genre which 99.99% of the time is just a losing battle from the start. Though it felt like the author didnt know how to write slower moments and transitions between scenes properly so things were rushed from the start for example the initial 4 year time skip and the transition to the enterance exam after it was explained to the exam takers.