You guys have probably read stuff like Gakusen Toshi Asteriks, Seirei Tsukai no Kenbu, Shinmai Maou no Keiyakusha and Infinite Stratos. Well, Magika no Kenshi to Shoukan Maou is basically a mix of all the series above.
You get the one male in the sea of woman plot, you get the tsundere with the power related to fire heroine, you get an extra harem member per volume, and you get a sword wielding harem king protagonist to wrap it all. It's mainstream? yes. So what's the difference between this series and the other?
First thing first, you can't blame the protagonist for collecting harem member. His whole magic abilities revolve around the love level of his harem girl. The stronger the love, the stronger magic he got. The more girl he get, the more variation of magic he got. He do care for his girls and don't act like some dense idiot. He is proactive, know when to act, and not boring.
Second, there is a plot. No, seriously there is one. His enemies is competent and doesn't make the protagonist group look OP. The universe is widening little by little. And you won't get stuck reading a story where the enemies attack come whenever the school is undergoing some kind of event.(Raise both third finger towards the IS universe, please.) So yes, the story itself is actually not half bad.
All in all, it's quite a good read to pass the time. The current translator is getting his job done pretty quickly and quite well, so you won't have to wait that long for a new update. You should give it a try when you don't have anything to do. You might unexpectedly like it.