5 MCU Storylines and Characters That Will Never Get Paid Off Before Avengers: Doomsday and the End of the Multiverse Saga
Spider-Man: Brand New Day is in theaters now, and Peter Parker’s (Tom Holland) fourth solo outing has already made box office history, surpassing Avengers: Endgame for the biggest domestic opening weekend ever recorded. That’s all the more impressive since Endgame served as the endpoint of a decade of Marvel Cinematic Universe storytelling, while Brand New Day functions as a standalone bridge into the next one. The movie’s record-breaking debut also lands months before Avengers: Doomsday, Marvel Studios’ answer to Infinity War, with Avengers: Secret Wars following a year later in the role Endgame once played. The pairing is designed to close out the Multiverse Saga the same way the Russo Brothers’ two-part finale closed the Infinity Saga, setting the stage for whatever comes next.
Where the Infinity Saga left relatively few dangling threads by the time Endgame arrived, the Multiverse Saga has accumulated a backlog of unresolved storylines across its movies and Disney+ series. Some, as the mysterious origins behind Shang-Chi’s (Simu Liu) rings, remain flexible enough that Doomsday or Secret Wars could still fold them into their narrative without much trouble. Others were seeded in projects with no clear route back to the main stage before the saga’s two-part send-off, and a handful may not resurface until Marvel Studios finishes rebuilding its universe on the other side of Secret Wars, if they return at all.
5) The Hulk’s Son, Skaar
She-Hulk: Attorney at Law ended its 2022 season with an unexplained reveal, showing Bruce Banner (Mark Ruffalo) returning from a trip to Sakaar with a previously unknown son, Skaar (Wil Deusner), in tow. In the comics, Skaar is born from Banner’s time on Sakaar during the “Planet Hulk” arc and grows into a central figure of the subsequent “World War Hulk” storyline, one of the more brutal chapters in the character’s history. Since Thor: Ragnarok already partially adapts the Planet Hulk storyline, the MCU needs to give Skaar a new origin and role, but She-Hulk: Attorney at Law offered no context for the character’s existence.
Spider-Man: Brand New Day, which brought Ruffalo back into the fold for the first time since She-Hulk, does little to close that gap. A framed photo of Skaar sits on Banner’s desk during a brief classroom scene, a blink-and-miss-it Easter egg that director Destin Daniel Cretton confirmed was intentional. Still, we never learn where Skaar is or what his relation with Banner. With Hulk himself absent from the confirmed Avengers: Doomsday roster, and Banner committed to psychiatric care, Skaar’s story has nowhere left to go before Secret Wars.
4) The Power Broker’s Fate
The Falcon and the Winter Soldier closed its 2021 season by revealing that Sharon Carter (Emily VanCamp) had spent the years since Captain America: Civil War building a criminal empire in Madripoor under the alias the Power Broker. The twist reframed one of Captain America’s most trusted allies into one of the biggest criminal players of the MCU. The reveal drew significant backlash for how little it squared with the character’s established loyalty, and instead of addressing the question by giving Sharon her redemption or committing to the bit, Marvel Studios has left her fate unresolved.
VanCamp has not physically reprised the role in any project set on the Sacred Timeline, appearing only in voice form for an alternate timeline in What If…? Disappointingly, neither Captain America: Brave New World nor Thunderbolts* found room to address what Sharon Carter has been doing with her restored government access. With Sam Wilson (Anthony Mackie) now positioned for Avengers: Doomsday and no announced project centered on Madripoor or its underworld, Carter’s villainous role has become one of the Phase 4 twists that will never receive a follow-up before the Multiverse Saga wraps.
3) The Role of the New Ten Rings Organization
Shang-Chi and the Legend of the Ten Rings ended with Xu Xialing (Meng’er Zhang) quietly seizing control of her father’s criminal organization rather than dismantling it as she had promised her brother, restructuring the Ten Rings with a new roster that notably included women her father had always excluded. A title card promised the group would return, a tease that has now sat unfulfilled for half a decade.
Xialing’s takeover raises obvious questions about what the reorganized Ten Rings intends to do with its resources and reach, but none of that has been explored on screen since 2021. Shang-Chi is confirmed to return in Avengers: Doomsday, and reports indicate Zhang could reprise Xialing alongside him. However, it’s unlikely the Ten Rings as an organization factors into a multiversal plot that includes at least three different universes and the TVA. That leaves the group’s rebuilt purpose as one of the more overlooked threads heading into the Multiverse Saga’s conclusion.
2) The Vibranium/Adamantium Arms Race
Black Panther: Wakanda Forever established Wakanda’s global standing as increasingly precarious, with Valentina Allegra de Fontaine’s CIA vibranium extraction efforts provoking a war with Namor’s (Tenoch Huerta Mejía) underwater kingdom of Talokan. Captain America: Brave New World escalated that tension by introducing adamantium, a metal discovered inside the remains of the Celestial Tiamut in the Indian Ocean and framed by President Ross (Harrison Ford) as a direct replacement for Wakanda’s vibranium monopoly, one strong enough to reshape the global balance of power. The film ends with the beginnings of an international treaty over adamantium’s distribution, a plot point that positioned world governments and Wakanda on a collision course.
Marvel Studios announced Black Panther 3 at San Diego Comic-Con 2026 with a release date of December 15, 2028, placing Wakanda’s next chapter a full year after Secret Wars closes out the Multiverse Saga. That gap means the vibranium and adamantium standoff, along with whatever fallout the Multiverse Saga’s ending brings to Wakanda, will sit unaddressed for years, with the adult T’Challa II (David Jonsson) inheriting a geopolitical crisis that the current saga set up but will not have time to finish.
1) The Influence of Mephisto Over Ironheart
Ironheart closed its 2025 season with the MCU’s long-teased introduction of Mephisto (Sacha Baron Cohen), revealed as the demon who empowered Parker Robbins (Anthony Ramos) throughout the series. In the series finale, Mephisto extended a similar offer to Riri Williams (Dominique Thorne), bringing her deceased friend Natalie back to life in exchange for an arrangement the show never fully specified. The series ended with Riri meddling with dark magic to power her armor, and her deal with Mephisto left open enough to suggest grim consequences down the line.
Marvel Studios is not pursuing a second season of Ironheart, and Thorne is not expected to appear in Avengers: Doomsday, despite her own comments in 2025 suggesting the odds were in her favor. That leaves one of Marvel Comics’ biggest villains, a character whose comic book history includes manipulating heroes across decades of stories, introduced to the MCU with no confirmed venue to continue his storyline. Of course, Mephisto is expected to appear in 2028’s Ghost Rider, given his comic book history with the Spirit of Vengeance. However, it’s unlikely that movie will have the time to deal with Riri Williams, which means even after Secret Wars closes out the saga, we don’t know when we’ll see the resolution of Ironheart‘s cliffhanger.
