It being the Asset, of course. He remembers how Soldat refused to accept their personhood on arrival. That fragment of themself, more thing, more weapon, than human, exists in some confused state still - and that's fine so long as it doesn't become a hazard but of course he's worried about that possibility before Soldat even brings it up. It's almost helpful to hear them confirm they're aware of the risk.

He'll let the thing about Sora go. Guy's weird. Needs to pick his friends better.

"The problem, of course, is that nobody knows how containable something like that is. It would be one thing if it was just a part of you and what you went through. But the things that happened to my lantern twisted me into something I've never been. Manage it as well as you can, but we should be looking into causes. Maybe fixes."

Dr. Solis must know about this. He resolves to write to her after this conversation. She's the only one he can think of who handles lanterns enough to have a guess about what's going on.