So, what do you think all these lessons that Magic Man is teaching Finn will amount to? I'm curious to see why he wants Finn to know so much about relationships...
lemme see how much of Magic Man I can tackle in one post.
Freak City: Magic Man is lonely and depressed. Finn thinks he can help by giving him a sugar cube. Magic Man teaches Finn what it’s really like to be lonely and depressed.
Sons of Mars: we learn that Magic Man had a relationship with Margles that ended tragically and turned him into the sad outcast jerk he is today. he hides his feelings, which is why he can’t activate the transporter. near the end he stares sadly at a photo of Margles, showing emotion for the first time. Tiny Manticore speech for emphasis.
All the Little People: Finn is curious about shipping. Magic Man teaches Finn about the little people. Finn becomes a god, controls the little people, ruins their relationships. they go “wawawa!”
Frost & Fire: Finn goes “wawawa!” after he’s controlled by the Cosmic Owl and ruins his relationship. Finn is a little person. Flame Princess breaks up with him because “the little people get left behind”, and since Magic Man sang those lyrics, it’s likely that his relationship with Margles ended similarly. perhaps the divine influence was Grob Gob Glob Grod.
Time Sandwich: after learning the importance of sadness in Sons of Mars, Magic Man teaches Jake to stop hiding his emotions behind silliness and drama and just express some honest sadness so he can fully appreciate what he has before it’s gone. this is interesting because Finn is still getting over Flame Princess, and, again paralleling Magic Man, Finn hasn’t cried. in The Pit he smiles about it.
oh and while I’m here, my headcanon is that Magic Man tried to magically revive Margles and ended up doing terrible things: turning her inside-out, tearing her apart. this is where he gets his fascination with body horror.