Board Thread:Questions and Answers/@comment-13439417-20151115150226/@comment-26418938-20151122005250

I know this might sound like crap but maybe there was a pre-incarnation of Liz, maybe Liz is an entity that must always exist so if she died another one would born, which is why one might exist 3000 years ago. So maybe Meliodas met a Liz possibly a member of the Goddess Clan and got influenced by her that caused him to betrayed the demon clan.

Remember when the one of the Goddess member wants Meliodas dead. Maybe this is also or is the reason. A demon in love with a Goddess, while the goddess and demon clan is oil and water.