I threw words like 2 birds, that's Batman and Robin
Lupe has thrown his own pieces of paper, lyrics, into the world.
The 2 birds are paper planes/birds. The Proust of Rap then references two superheroes from DC Comics, Batman & Robin.
Both bats and robins fly, though only the latter is a bird.
In the original Batman TV show, while they “threw” punches in the fight scenes, you would see actual words pop onto the screen like “pow” and “bang” so essentially they were throwing words, fitting in with the next line.
In context with the following line about his “beef” with Childish Gambino, gone into depth in the following explanation, he could be saying that he is a dark knight, a hero that is unwanted.
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