Oh Keine! This looks awesome! I'm thinking about cosplaying as Keine too (probably the human form though), so your cosplay was a good inspiration : ) It's very well done and looks very good in you! Good job!
You did a very nice job with the dress, the scroll, those horns... and is that a tail? xD I like the detailing on the ends of the dress, and I'm impressed how you managed to make the horns and make it look so seamless with the rest of the headpiece. Nice job!