A clever use of the FIST system, which proves that the system can be used for fantasy. But really, this does not feel like FIST and does feel fully standalone. 

The magical girl in an otherwise traditional European fantasy world (leaning a bit towards fairy tale) is an eccentric choice but it is unique and welcome. 

There is something a bit odd about roleplaying carrying a body on a long journey. I was the designated corpse carrier (in a play-by-post campaign) and we decided I needed to have some kind of harness. It was easy to forget about the body, but that can itself have great roleplaying opportunities. 

All in all, a good, original vibe.