Thanatos remains silent, but his focus isn't on the butterfly with the hitchhiking soul. He watches Ryo and doesn't give any indication whether or not he hears the soul speak. It's like he's a statue of stone, not interfering and just in the scenery. Ryo has to decide how this progresses instead of pushing this onto Thanatos "because he's Death."

Ryo sounds very surprised that this conversation is happening. This isn't normal for him and might not be something possible in his world. Is it just the ability to speak to the shades of the dead or something more? This is not the power Ryo had in the false Diagad whatever this is, and even Ryo will have to see the truth of it. He's no danger to the living.