Crowley half shrugged, not even sure how to explain it. Even he didn't know the true limits of Lucifer's power. Right now the only reason he had any at all was because he wasn't in his true vessel, Sam Winchester, the bloodline Lucifer needed. Michael and Lucifer, Dean and Sam, brother against brother, all very biblical and melodramatic, and wasn't that just the way of angels. "You know the myths of Lucifer, with the seductions and ways with words, slipping into your mind, tempting you. It's all part of that. Hell, demons can do it too, just not nearly as well as he can." Crowley himself could exert pressure on other minds, weasel his way in to find out what would tempt them the most, lure them into making deals. Nothing too invasive, just a nudge in the right direction. "He created the first demon, Lilith, and all of us, we come from that. He is linked to us all, as much as he loathes every one of us." Most demons didn't see it, too seduced by their lord and master, their beloved father, but Crowley had always been something of a pragmatist.
He shifted to mirror Kol's position, without even realizing it, frowning a little at the idea of letting Kol into his head. "Not that you're asking," he echoed the statement back with a faint smirk before it faded. "Not sure you'd want to go poking around in here, darling." The endearment slipped out with somewhat less of the usual amount of sarcasm, as Crowley tapped the side of his head. "Might see some things you don't like, and I'm not talking about the massacres, we both know your reactions to those." Hell, Crowley still had the remnants of the bite marks on his neck to prove it. "It's Hell in here, literally." Kol had gone into the minds of humans before, possibly even other vampires, but a demon was another matter. A black and twisted remains of a soul, carved into shape by the Pit. Crowley was used to it by now, but he wasn't sure how he'd feel if Kol went in there and recoiled from what he saw.
"Well, maybe we should just try some time anyway, in the name of science, of course." Because hey, it was an interesting idea, if Crowley could actually make Kol so senseless that even he wouldn't wake up at movements.