The Seven deadly Sins: Travel for the Eight Sin

Everyone knows about the Seven deadly sins and their journey to protect the kingdoms from the New Generation of Holy Knights, The Ten Commandments, and The Six Black Knights. But what if there was another threat to the kingdom that is more powerful than The Seven Deathly Sins and was planing of bringing back all of there past enemies to defeat them and take over the kingdom of Liones. When the Sins' receive a message from an old clan that created all the clans, they head on a journey to find the Eight sin. (P.S. sorry for any miss any miss spelling or grammar also I don' t own any of the seven deadly sins characters and this is my first story.)