This is just a thought and you don't have to take it seriously, this is definitely the theory I believe the least, but it doesn't hurt to elaborate a little bit, I know that as soon as chapter 5 came out some people also thought about this possibility, but I'd like to delve a little deeper. What if Mael is one of the 4 horsemen of the apocalypse? More specifically the Plague Knight, his silhouette definitely looks like Mael, especially when he wore armor, Mael lost his old sword so this could definitely be his new one, the fact that this knight has meanness and sanctity in his eyes could be a reference to that fact. that Mael was once Estarossa, a demon, he was once a demon and an angel and even used the powers of the two clans together for a short period of time. But wouldn't it make more sense for Mael to be the one with golden magic? This is where my theory comes in, no, because Mael will not use Sunshine, she will have a new heir as per the drafts, but how would Mael be one of the 4 knights without her grace? Well, achieving a new transformation, Mael was the most powerful of the goddess clan, while Meliodas was the strongest of the demon clan, so if Meliodas achieved a demon king form it is possible that Mael assumes a goddess king form, that it would make him more powerful than if he had sunshine, guaranteeing his place in the group. I would really find this an interesting and different proposal, as Nakaba never gave its due value to the goddess clan, if one of the 4 knights of the apocalypse was a member of the goddess clan it would be really cool.

https://preview.redd.it/zs9jlsqwe1581.jpg?width=694&format=pjpg&auto=webp&s=509cd31f600d1c8c6af6dd2eb184333b9fd71789

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