Professor Genius acts as King Morpheus's chief advisor in Slumberland, mentoring the young protagonist Nemo. His duties involve guiding Nemo to recognize his potential strength and protecting the realm from threats like the Nightmare King. Typically sophisticated and punctual, favoring order, he nonetheless breaks into moments of expressiveness, such as enthusiastic dancing during ceremonies. He transports Nemo to Slumberland via dirigible and oversees the boy's introduction to royal duties and prince lessons. He sternly forbids opening a specific door marked with a dragon insignia, a prohibition later violated. When the Nightmare King is unleashed, Professor Genius initially displays cowardice but shifts toward compassion and loyalty. He reassures Nemo against excessive self-blame for the catastrophe and actively joins the mission to rescue the captured King Morpheus. He participates in the perilous journey through Nightmare Land, demonstrating commitment to restoring Slumberland's safety. Throughout, he maintains a consistently negative view of the disruptive clown Flip, whom he deems a "frightful fellow" due to Flip's chaotic influence, contrasting his supportive demeanor toward Nemo and allies. In the real world, he manifests as an organ player in a visiting circus parade, connecting his presence across realms. His background reveals no earlier history or alternate media expansions beyond his established advisory and protective functions within the core storyline.