He did feel it. And Stiles didn't know what it would mean either. For now or in the near distant future. The thought of Lucifer somehow using it against him, to maybe hurt his friends, to hurt Lydia...it made him feel sick to his stomach. "Yeah, I know you'd knock me out." He took a step closer to Derek, his expression growing grimmer. "But if it takes more than knocking me unconscious to keep me from hurting anyone -- you do what you have to do."
He knew he wasn't going to have to spell that out for Derek anymore than he already had. He drew in a breath and let it out slowly, looking down at the ground, troubled. "Nightmares. A lot of them. I don't remember all the details, but I do remember they all involve seeing blood -- a lot of blood -- on my clothes." He paused. "On my hands." He didn't know if it was some kind of prophetic thing, or just his worst fear playing itself out over and over in his head.
Derek would probably be surprised to know that while Stiles didn't fully trust him, he did believe Derek wanted them all to be safe. And he believed if it came down to it, Derek would be the one person that could be depended on to do whatever had to be done.