For those that don't know what the term a 'Marx' is, it's basically a term that people call to other game characters whenever they betray the main character after getting what he/she needed.
Long story short: Pyrrhon betrayed Pit.
Where the 'Marx' term came from, it came from two games in the Kirby series: Kirby Super Star and Kirby Super Star Ultra (they're both the same but Ultra is way better) and the character named Marx. Marx duped Kirby to help him achieve a certain goal, and according to Pyrrhon's article page, it's possible that Pyrrhon summoned the Aurum himself. Pyrrhon used Pit, Palutena, Viridi, and even Hades by making up a fake propehcy, and his attempt to take over the Aurum himself. From this, Pyrrhon attacked Pit, giving a white flag that 'Pyrrhon pulled another Marx on us' signal.
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