The one thing James Gunn can do with DC that he didn't do with Marvel
James Gunn is currently planning the future of the DCU, and his plans for the franchise could involve something he's never done with Marvel.

In his leadership role at the newly formed DC Studios, James Gunn can realize an opportunity he missed during his time in the MCU. After entering the DCEU with 2021's Suicide Squad and its spinoff, Peacemakers, Gunn is helping shape the franchise's future as co-CEO of DC Studios alongside Peter Safran. Gunn and Safran are developing a 10-year plan in the "DC bible," which will include DC movies, TV shows, animation and video games.
Prior to working on the newly renamed DCU, James Gunn was known as the director of the MCU's Guardians of the Galaxy series. His early involvement with DC Studios also overlapped with his final Marvel projects, Guardians of the Galaxy Holiday Special and 2023's Guardians of the Galaxy Vol. 3. In the meantime, Gunn's role in overseeing the future of the DCU could restore the important role he was once rumored to have in the larger MCU.
James Gunn Was Involved In Marvel's Cosmic Universe
After the release of Guardians of the Galaxy Vol. 2. James Gunn is rumored to be the cosmic architect of the Marvel Cinematic Universe. Kevin Feige later clarified that Gunn's work in the Guardians of the Galaxy films was just the groundwork For Marvel's cosmic elements. After Gunn fires from Guardians of the Galaxy Vol. 3 He was eventually rehired by Disney due to controversial tweets in the past, but Gunn's career situation became more complicated.
James Gunn was on Suicide Squad between his firing and his subsequent rehiring by Disney. In that time frame, it's not just a release date for Guardians of the Galaxy Vol. 3 was pushed back, but Gunn's various DC projects no longer allowed him to commit to actively working on the MCU full-time. However, Gunn can now draw elements of DC's universe for Marvel as he was once rumored to.
How Gunn Could Map The Cosmic Elements Of The DCU

As creative lead at DC Studios, Gunn is directly involved with every upcoming DCU project beyond 2023 (Matt Reeves' Batman universe and Todd Phillips' Joker movie are planned independently of the DCU). By default, Gunn will oversee the Green Lantern Corps, New Gods, and every other universe-based character in the DCU. While the filmmakers are said to be given considerable latitude under the leadership of DC Studios, the overall roadmap of where they're going is in Gunn's hands.
There is also a great There are a lot of unanswered questions about what exactly the DCU will need, though Gunn is often on Twitter to provide as much clarity as possible. Regardless, based on DC Studios' 10-year plan, the future of the DCU will likely venture into the stars and the wider multiverse just like Earth itself. James Gunn's plan with DC Studios, which he describes as "the greatest story ever written," could bring in many DC Universe stories and characters, including those making their big-screen debuts.