I don't think there's such thing..
If there was Epicwar should be filled with the FOC-map with Naruto(??),
and if Naruto was ever been put in the game he would be totally imba, i mean kyuubi, kage-bunshin, rasengan, sage mode- all imba attacks(i know i'm a hardcore naruto fan), maybe the one who you saw playing edited the map or maybe it's not FOC. You can try NBR-Naruto Battle Royal totally cool game with nice skins and it has Naruto in it! You can download it in here: http://epicwar.com/maps/101020/ if you're interested ^^./.