It is a manga written by Butre and illustrated by lostperras. It is in English and can be purchased at Gumroad: http://butre3004.deviantart.com/art/Kannagi-s-epic-story-606853676
Officially: This month we launched an anime-style comic in collaboration with LostPerras, called "Kannagi's epic story" and tells the story of an evil girl, who discovers powers that allow her to go through a dimensional portal to a parallel world where people live little. She takes advantage of these people doing evil things to her.
There are only 3: