Blood Moon Ahri
league of legends ahri skin project by rhose chan-d8b28ku
Ahri is a mage assassin, so I believe she deserves a blood moon skin! :D
Here are some other skins to check out :)
Halloween Syndra
http://boards.na.leagueoflegends.com/en/c/skin-champion-concepts/IEHllEle-halloween-syndra
Vampiric Ahri
http://boards.na.leagueoflegends.com/en/c/skin-champion-concepts/02MaEdEn-vampiric-ahri