I don't think its Seina going rage mode that killed their mother since we do see Fumina witnessing it first hand back when she was a literal child, so its seperate character and since she's the older sister, Seina might've been a baby at that point. (This is from Chapter 9.5 - The Volume 1 extras)
Its doing pretty good despite being a fairly new series.
It ranked 32nd on its 2nd volume release on a top 500 manga ranking list (Link: http://shosekiranking.blog.fc2.com/blog-entry-5544.html)
and it ranked 7th on the Mangaone app (Shogakukan publishing app) back in january til the whole drama...
Something interesting that I found while re-reading Fist of the Seeker (The author's first ever work). Here's the comparison between the movesets of Tsubaki and Zong Longshen (the grandson of the founder of the martial art that was mentioned by Maya in the previous chapter).
Speaking of Fist of the Seeker (For anyone that's wondering, this is the author's first ever "manga" he made. Its very amatuerish)
- There are even more connections to the storyline than we thought. Apparently the Hell's Gate drug might've appeared back in FoTS arc 2 where a character named...
The colored pages at the end of each chapter are from the extras that is in the digital version of the chapters itself not from the volumes both physical and digital. I think the only bonuses the Volume has are the character profiles and the side story. Other than that most of the bonus artwork...