Based on the article and the poll, the most exciting DC character in James Gunn's Superman reboot — especially with the fresh, bold direction being taken — is Nathan Fillion's Guy Gardner.

Here’s why:

• A completely reimagined take: Unlike previous portrayals, Fillion’s Guy Gardner is not just a tough guy with a badge — he’s intentionally not a "nice person." This makes him a standout in a world where heroism often comes with moral righteousness. His fearlessness without goodness is a refreshing, edgy twist.
• Unapologetic villain energy: Fillion himself calls him a "jerk," which adds depth and unpredictability. His self-serving, arrogant, and overconfident nature — even believing he could beat Superman — makes him a fascinating antagonist or antihero.
• Narrative freedom: This version of Guy Gardner breaks the mold of the typically heroic Green Lantern. It opens up new storytelling possibilities, especially in a DCU where characters aren’t bound by legacy expectations.
• Casting synergy: Nathan Fillion’s charisma and comedic timing (from Guardians of the Galaxy, The Rocketeer, Castle) make him a perfect fit to play a flawed, loud, and chaotic hero who’s as dangerous as he is entertaining.

While fans are excited for David Corenswet’s Superman, Rachel Brosnahan’s Lois Lane, or Nicholas Hoult’s Lex Luthor, Fillion’s Guy Gardner stands out as the most surprising and bold addition — a character who promises to bring both chaos and charisma to the new DCU.

So, the winner?
👉 Nathan Fillion's Guy Gardner — because in a world full of "good" heroes, the one who’s fearless and selfish might just be the most fun to watch.