With Ren looking on, Willie became more solid. Maybe he was a ghost, but if so, he seemed to be smarter or more active than the others. This was all just a guess on Ren's part and he was sure he might be able to just ask later. The partially-transparent form didn't bother Ren nearly as much as it did others. Most Personas looked that way when called on, so that was nothing new, and some Personas looked far more monstrous than Willie did. When Willie smiled and extended his hand, Ren returned the gesture.
It was just polite and Willie seemed nice enough. "Nice to meet you." He repeated, warming slightly as well. Then he pulled his hand back and nodded. "I don't understand what you mean, but I think I get some of it. Are you a ghost, like the others here?"