Let's face the facts. Most of the obvious choices for Donald Glover's casting are only "obvious" for superficial reasons. We want him to be Miles Morales because we fondly remember how much life Glover brought to the role of Troy Barnes in Community, as well as the voice for the character on Ultimate Spider-Man.
We sort of expect him to play Randy Robertson or Flash Thompson, even though he doesn't share similar physicality with those characters. And for that same reason his casting as Harry Osborn would also be a jarring decision, considering the youthful appearance of Tom Holland, who is the new MCU Spider-Man.
But these characters are just too young, and while spritely, Glover is not young. He's a 32-year-old seasoned comedic actor at this point (just look at how easily he acclimated to the tone of The Martian), and he deserves more than a token casting or relegation to the slot reserved for side characters with brief screen time.
In other words, Donald Glover is a huge get for Marvel, and his complex acting style could very well fix a huge problem the studio has been experiencing with few exceptions: Crafting memorable and relatable villains.
In more other words, there are far better roles more deserving of Glover's talent in the villainy pool, and numbers alone tell us that he'll probably be a bad guy.
Michael Keaton is already rumored to play the Big Bad of Homecoming — the Vulture. And mixing in more than one key villain in a debut film is counterintuitive to Marvel's cinematic playbook thus far. That doesn't mean Glover would have to play a one-and-done antagonist similar to Tony Stark's kidnappers or Baskin Robbins, but rather, a soft villain who could be built up over the course of a few movies.
That Villain Could Easily Be Eddie Brock
Eddie Brock, or Venom as he's more commonly known, is already established as someone older than Peter, but not that much older. Great iterations of Brock (like in The Spectacular Spider-Man) have started him out as Peter's older friend and mentor, even when it comes to his science skills and burgeoning career as a photographer.
Brock's ascent to villainy is slower and more dramatic in its best retellings, painting him as a counter to Peter Parker through a series of mistakes he makes at his friend's expense. Glover himself has shown incredible emotional range to that point through his rapping career and even some of Community's more serious episodes.
And Eddie Brock is only one of many potential villains the MCU can plant a seed for with Glover, effectively providing a more cohesive sandbox for its bad guys, rather than the "villain of the week" formula. The Tinkerer (who already has clear ties to Vulture), Mysterio, Shocker, Hydro-Man, Prowler, Carnage, Scorpion, Jackal and even Chameleon are all fine candidates for similar reasons.
Of course, it's possible, if not a little unlikely, that Marvel will position Glover as a protagonist or neutral character. But judging from what we know about Spider-Man lore, Glover himself, and how Marvel likes to craft origin stories with some emotional punch, that just seems like a complete miscalculation.
Which villain do you think Donald Glover will play?