Presto mentally winces. It's never as easy as they think it is. The damage wrought at the fortress took a lot out of him. He's by no means finished, but there would be some mental fog to contend with.
"The same way we kill anything else, really. If it moves around on its own, it can be killed, even if it's made of air, enchanted by magic, or summoned from another place entirely. There are rules to this sort of thing." Presto shrugs.
"My main concern is how to get past them. They can definitely be killed, but they probably won't be easy to kill. And it seems too easy to have a few entrances to the tower guarded and have that be the only obstacle. It's never that simple. I have ways to get myself around, but I'm not used to passengers. Diana and Sheila move around pretty well on their own. Bobby, Hank, and Eric, do you know if you can get above, below, through, or around them without having to fight? I might be able to take one person, but it would be a risk."