@So-chan i don't know if this will get better or not, it's currently 7/10 rating for me. I recommend reading Blade Note, it has same setting like this, modern day revenge story of a guy with a sword/magic sword, but more awesome fight and story.
if you want more Manga like this, check "hinomoto sanshimai wa kamatte hoshii" from this manga author. it's completed but only 10 chapter translated to English. i think it's more wholesome than this
at Vampire lord arc, i still don't know what Rave Master Haru said to The Penguin (forgot his name) about who will be his successor if he die fighting the vampire lord (forgot his name)
i remember a theme like this before, about a man who have one ultimate wish from God / Goddess in exchange for his life, but he wish to marry her instead. Does anyone know the manga series title for that?