The characters are really well made and the art is very well suited to the manga .
The MC does things for revenge and once he thought he achieved it he realises that it doesn't bring back his sister. And once he realises the person he was seeking revenge on was alive he didn't just kill him on the spot but thought about it. and the realise the only reason he was so hellbent on seeking revenge was because he wanted a reason to go on. And he ended up kill him anyways without realising it. and he also accidentally killed his friend
After all that happened he got his sister back and he was finally happy but he ended up having to face the pass.
From this the MC learns that you don't choose who you are the world does.