I was wondering why these looked familiar, then I remembered. These are rough sketches for a doujinshi called "Taikyuu spell wa ikaga". Specifically, these are for the mini-story at the back of the doujin.
It would be preferable to have the finished versions of these pages posted too. I only have the translated version on my HDD at the moment, but give me and a minute and I'll see if I can track down the originals.