So, it was brought to my attention that I didn't make something clear. Let me rectify that. I personally do not think that Ban is weaker than the other Sins. However, I do believe that they all thought that at first, except of course Meliodas. Part of this story is them realizing that Ban isn't as weak as they all thought.
I do not own the Seven Deadly Sins, or anything else that is recognized.
Sacred Treasure
Ban didn't use his Sacred Treasure to fight.
That was one of the first things the rest of the Seven Deadly Sins noticed about him. Instead of using the sword by his side that was a sacred weapon, he would always use nun-chucks, sometimes even setting the sheathed sword to the ground if it would get in the way of his fighting.
That did not mean that he wasn't protective over his weapon, as they all tended to be, in fact he seemed even more possessive about that sword than Meliodas was about either of his blades.
But it made no sense to any of them, because even when Ban was beaten into the ground he still didn't release the sword's power. He never even mentioned it's name, or spoke like it was even an option to use during the fight.
Merlin was curious. She knew all of the other weapons, but Ban's. And even if he was not nearly as powerful as the rest of them from his own lack of experience, Ban did have the potential to get there one day. In a couple of centuries. So she wanted to know what sort of weapon he would have.
She brought up the subject one night, "Ban, what is your sword, what does it do? I have never heard of a sacred treasure that looks like that before. And you never even use it."
And as all the rest of the Sins turned to look at Ban and Merlin, it was King who spoke up, "Yeah, why don't you use that sword?"
As they all continued talking about it, led by Merlin, only Meliodas noticed the expression on Ban's face. It was overcast, and almost in a grimace, but what really struck a chord in Meliodas… was the fact that Ban seemed terrified of something.
"Guys, if Ban doesn't want to talk about it, he doesn't have to. I trust him," Meliodas interjected with a cheerful tone. Everyone sort of collapsed, with Merlin being upset about it but respecting her captain's wishes in this. Besides, she thought, Ban didn't have the same strength as the rest of the Sins, so it probably was nothing very special.
"It's fine," Ban says very softly, "You guys should probably know why I won't want to use this sword unless we're all about to die, anyway."
Everyone gathered around the fire, as Ban put his sword across his lap. He seemed far more serious and sober than normal, looking down at the sword. It wasn't even very ornate, or special looking in the sheath, and seemed like something any random knight might have.
"If you ever see me pull this sword out of its sheath, I'd do your best to stand back," Ban started, as he tilted his head up and closed his eyes, before sighing, "I can't guarantee that I'll see you as friends, and even if I do I don't think I'll be very good at controlling myself. I don't think what would happen will be enough to kill any of you guys, but people weaker than you might end up dying."
"You would be strong enough to kill people by accident?" Merlin questioned.
"I… after all of this time, and in the midst of the type of battle where I'd have to unsheathe my sword, I would probably lose myself and my control. And I wouldn't want to hurt anyone."
And with those parting words, Ban stood up and walked away. Leaving even more questions in the heads of the rest of the Seven Deadly Sins, and a doubt that he was as weak as they had all thought.
It wouldn't be until the first time he unsheathed that sword of his, however, that they realized that they had never truly been stronger than Ban, and that he had been able to stand amongst them from the start.
Yeah, I can't wait until we get to the actual story line. I have something good planned for it!