What types of videos do they most frequently explore (e.g., unsolved mysteries, urban legends, science fiction, history, etc.)?

Their most frequent topics are strange and curious things, such as unsolved mysteries, aliens, doomsday prophecies, and urban legends. You could also describe it as a "paranormal + popular science" hybrid style, covering subjects like the Bermuda Triangle, Nostradamus's prophecies, and parallel universes. They present these topics in a captivating and almost mythical way, yet always backed by some reasoning or evidence, making them incredibly engaging to listen to. Occasionally, they also discuss history or scientific knowledge, but their videos are essentially always centered around the theme of "what else is there in this world that we don't know?" Simply put, their signature content is the kind that leaves you too spooked to turn off the lights after watching it late at night.