Duster nods throughout Jack's explanation. He knew better than to interrupt someone in the middle of explaining something long and important, which branded him as an excellent listener to most people he met. He just didn't know any other way to deal with talking people.

Jade. Aoi. Rukia. Reno. Malik. Some he recognized more than others, but they were some strong people on their own. Except Aoi. How ironic that he died hours after his private lesson with Duster.

"...Do you think this is all one person? There's no way one guy can do that all by themselves."