In all honesty, Marian knew that both Robin and Will were right. She didn't want him anywhere near her either, but it seemed like at least this way she would know where he was. The not knowing and the waiting were both terrifying, and even knowing that the Sheriff was being held behind some sort of magic angel walls didn't quite stop that fear.
But now Will was standing in front of Marian with his firm hand on her shoulder, and Art was right behind with his own arms around her, and she felt tiny between those two tall men: tiny but protected.
The protection was an illusion though, just like it had been last time around. She looked up at Will and her face crumpled, the memory of them all together in those cells washing over her, the memory of the way the Sheriff had lashed him.
The memory of, later, going to bed with the very man who had lashed her him, who had starved them, who had brutalised them. The memory of sitting on the Sheriff's living room floor in Arizona and genuinely laughing as they played a board game, while her friends froze and stared to death on the other side of the country.
In some ways she and Will had this shared horror between them, but in other ways there was a chasm of difference between what had happened to them both, and she doubted she would ever be able to fully cross and understand it.
The Sheriff couldn't touch them, Marian had to believe that, but-
She sniffed, taking a deep breath and looking across at Robin, defiant although she knew it wasn't fair to direct it at Robin, as though he had done any of this. "The Sheriff doesn't need to be able to touch us, remember? He hired that demon. He had me tortured, non-stop, for eleven days." Robin was a little hard to see through the tears blurring her eyes. "Cattle prods and hot pokers and waterboarding and starvation and no peace except for when he let me sleep and the Sheriff didn't even need to be there for that." Maybe it was also unfair to use what had happened to her like a weapon (yes, it was unfair, there was no 'maybe') but how else to make it clear to all of them that it wasn't just the Sheriff's own hands she feared, but what he could put out there into the world?
Maybe Michael did have him locked up tight, and maybe there was no way he could get free, but the Sheriff had showed her he had other methods to break them down.