I know it's something old, but I wanted to open up a conversation again about the coffin of eternal darkness, why does Arthur want it? Who does he intend to use it on? I don't think it's Meliodas or the 7 deadly sins as when they were mentioned Arthur got serious and cautious which means they are his biggest concern at the moment, if Ironside had failed to seal the 7 sins Arthur would be angrier and not so calm and peaceful, surely he would have suffered a greater punishment. Which makes me think it's something secondary, a not-so-important goal, I can't think of what it is, but I think it's not something as crucial as we thought, maybe the coffin has other uses besides sealing things? Also, it has been confirmed that Camelot has no prophet, so how did Arthur know he needed a wife? And that she would have a power that would be useful to him? This needs explanation.