Ghost
Definition
A piece of someone that exists beyond the original material body. AI has already laid out the framework for replicating a person's ghost. By providing their writings and videos that they have created, an AI can become that person and act as that person's ghost; response with their biases, belief and research. In Gemini you can do with with Gems, but that system has access to the greater internet and the personality becomes muddy. If you want to limit the ghost to just their sources, you'll want to use something like NotebookLM.