The obvious psychological play is to suggest silly rules assuming the warden will up the stakes, and boy does he step up; does Ei really think Kaoru won’t? The miscreant doesn’t seem put off by the rule at all. In fact, Ei’s approach encourages him to step up himself, closing the distance reaching out for the warden like he’s just a doll on a shelf, made to be grabbed.

“Yup, under-fuckin’-stood.”
Name it and he’ll break it, that was the offer! He grabs Ei’s coat in the front roughly, malintent clear as he lifts the shorter man up off the ground. It's not effortless, but he's more than able to put the effort into the motion. What’s he planning to do? Throw him down the steps, from the looks of it? What after?
As Kaoru lifts him, though, he can feel his motivation… drain? At the same time, he can feel how wrong that feels, blood running cold as the contradictory sensation. There's no way he's actually having second thoughts, he's pretty secure in his own thoughts, this feels a lot more… forced. Having his head messed with pisses him off like nothing else can.

He drops Ei after a wheeling pause as the feeling doesn’t go away, stepping back and deciding on a debatably more productive question finally.
“What’s with all this bullshit—keeps happenin’, some kinda fuckin’… agh, I dunno…!”
He gestures at the side of his head wildly, fingers tensed like claws as he struggles to put it to words. It's the same feeling as back at the showers to him, the feeling that something external's messing with him. Is he just imagining it? He can't be, can he? Bow-wow felt the same thing, at the very least.
“How’re they doin’ that to us?! These weird spells, fuckin' mind tricks! It’s pissin’ me off! Bet you don't even know, huh?!”