It's a rough spell, something that would cut off anything in or out, enough he can try and calm Harry. It's something he had erected outside of dreams to protect himself and his mother many times when they were running. That was before the ICW approached him and offered them sanctuary.

Now it was benefiting him in helping Harry as well, and he's glad for it.

"Oh? I've been in your dreams before, Potter?" He smirks at that, arching a brow at him. "You should share those details," he teases, trying to distract him from how bad those dreams were. He knew how nightmares could be.

"Oh, definitely woke me. Those wards of yours are the only reason you haven't woken up everyone in the building. Luckily I'm better at getting into minds than you are in keeping me out."