Fans of the Souls series are still finding secrets hidden within the code of the games, even after all of these years.
There was once going to be a magic item in Dark Souls III, called the Ceremony Sword of Darkness, which had the power to shroud the High Wall of Lothric in darkness. This matches up with some of the early screenshots of the game, which show the High Wall of Lothric at nighttime, even though the time doesn't change that way in the final version of the game.
This dark version of the High Wall of Lothric is referred to within the game's files as the "Moonlight Ceremony state" which isn't as romantic as it sounds. The purpose of this ritual was to invite multiple players into a PvP battle royale.
There is another cut item, called the Ceremony Sword of Flame, which would allow players to invade a world that was under the effect of a Moonlight Ceremony.
There was yet another cut weapon, called the Ceremony Sword Battle Royale Eclipse (though that likely wouldn't have been its name in the final version of the game). This name suggests that the Moonlight Ceremony would be used to invite a group of players into a massive PvP arena battle on the High Wall of Lothric.
It's unknown why this awesome concept was cut from Dark Souls III. It's possible that the game had performance issues when too many players were in the same region at once, which makes sense, considering the fact that the Moonlight version of the High Wall of Lothric kept all of its regular enemies. This would also explain why this unused feature was never added in an update or as part of the DLC.
The Souls series is the gift that keeps on giving to data miners, as there is a ton of buried content throughout the series. These have included an entire missing region for The Land of Giants in Demon's Souls and several cut bosses in Bloodborne, including an unseen form for the final boss in the game. We can only wonder if Dark Souls III still has some more secrets to share.