We’ve seen Mark Ruffalo’s Hulk develop in interesting ways over the years. We’ve seen the Hulk refuse to come out of Banner, refuse to go back into Banner, get his anger under control, lose control of it, and finally, in Avengers: Endgame, we saw him get along with Banner and meet in the middle with “Professor Hulk,” the best of both worlds.

RELATED: 20 Things Only True Fans Know About Mark Ruffalo's Hulk

If a Hulk solo movie’s going to happen, now is the best time. Just in case the rights issues can be worked out with Universal and Ruffalo’s Hulk can finally get that solo movie, here are 10 Hulk Storylines A Possible MCU Solo Movie Could Adapt.

World War Hulk

“World War Hulk” was the sequel to “Planet Hulk,” which loosely formed the basis for Thor: Ragnarok, so it would make sense if it was the second Hulk storyline adapted for the MCU. In “Planet Hulk,” the Hulk was catapulted into space by a bunch of his fellow superheroes and ended up becoming a gladiator on a distant planet (sound familiar?).

After he and his gladiator buddies escaped, in “World War Hulk,” they returned to Earth to wreak havoc on the superheroes that cast him out in the first place. The specifics of the plot setup would have to be changed, but an out-of-control Hulk as a villain fighting the other Avengers is something we haven’t seen yet with Mark Ruffalo’s Hulk. It could be interesting.

The Battle of the Century

Fantastic Four Meet the Hulk

In the Fantastic Four storyline “The Battle of the Century,” the Hulk has just lost control and is being chased through the New Mexico desert by the U.S. government. When he hears that the Avengers have replaced him as leader with Captain America (this detail would need to be changed), he returns to New York where he’s faced with the Fantastic Four.

If Marvel Studios’ rights to the Hulk prevent them from doing a proper solo movie and they have to instead put him in other people’s movies like Thor: Ragnarok, then this would be a perfect way to blend the Fantastic Four’s introduction into the MCU with a second semi-solo movie for the Hulk.

Earth’s Mightiest Heroes

This storyline, which comprises the first three issues of Stan Lee and Jack Kirby’s Avengers run, would have to be tweaked slightly for a film adaptation, since the Avengers disbanded at the end of Endgame, and therefore there is no Avengers team in the MCU right now. However, with Loki sneakily escaping with the Cosmic Cube in 2012, there’s a way to do this one.

RELATED: Loki Is Alive After Avengers: Endgame (In A New MCU Timeline)

In the comic, Loki tricks the Avengers – Iron Man, the Wasp, Ant-Man, and Thor – into fighting the Hulk. Joss Whedon almost made the Hulk the main villain in The Avengers, so there’s probably an archive of concept art somewhere that can be used as a jumping-off point for this movie.

Return of the Monster

Bruce Jones and John Romita, Jr.’s “Return of the Monster” storyline is one of the Hulk’s most acclaimed comics. It’s very character-focused, which is what makes Mark Ruffalo’s Hulk arcs in the MCU such a joy. He plays Banner as a real guy with real ethics.

“Return of the Monster” sees Bruce blamed for the demise of a child that happened during one of the Hulk’s rampages, so he walks out on society and goes off the grid, hitchhiking like David Banner in the TV series. Over the course of this journey, Bruce grapples with the Hulk as his dark side. It would be a terrific dramatic culmination of all the Banner/Hulk interplay we’ve seen in the MCU so far.

Hulk and Thing: Hard Knocks

Hulk vs The Thing

This one would be tricky to pull off with rights issues, but as the Disney/Fox merger quickly goes through, an adaptation of the “Hulk and Thing: Hard Knocks” storyline doesn’t sound so far-fetched. It begins with Bruce Banner having a quiet time in a diner when suddenly, the Thing from the Fantastic Four shows up and sits opposite him.

The Thing smacks Banner to turn him into “the other guy,” and what follows is a tense conversation about their troubled relationship, punctuated by incredible fight scenes. It would be a weird one, but after the surreal odyssey of Endgame (Lebowski Thor, Professor Hulk, time travel, tacos, unconventional story structure etc.), it could feed into the MCU’s new direction.

Gray

Jeph Loeb and Tim Sale did a whole Marvel Comics series with the theme of “Colors.” They did books called “Captain America: White,” “Spider-Man: Blue,” and “Daredevil: Yellow.” The one they did for Hulk, “Hulk: Gray,” would make a pretty great movie.

It has a bleak color palette, with its opening scene even being depicted in black-and-white (it’s about time the MCU experimented with black-and-white – not for a whole movie, but for a scene or two like in this comic). The comic tells an alternate origin story where the Hulk was gray in his earliest incarnation as opposed to green, all the while framed by a present-day tale in which something bad happened on Bruce and Betty’s anniversary.

Always On My Mind

For a while now, MCU fans have wondered if we’ll ever see the sequel setups in The Incredible Hulk pay off. The return of Thunderbolt Ross in the recent, more politically charged MCU team-ups has suggested that Marvel isn’t pretending that The Incredible Hulk never happened like the rest of us are. A Hulk solo movie might as well follow up on these things. What happened to Liv Tyler’s Betty Ross? What happened to Tim Roth’s Abomination?

RELATED: All References To The Incredible Hulk In Later MCU Movies (That Prove It's Canon)

“Always On My Mind” could answer all these questions. Betty has been hiding out, teaching writing classes, when the Abomination suddenly resurfaces and kills her. This leads to a brutal showdown between the Hulk and the Abomination. It’s not the most complex story, but it does offer an opportunity for ample Hulk action and a soft redo of The Incredible Hulk.

Tempest Fugit

In a pastiche of the seminal sci-fi movie Forbidden Planet, or more overtly William Shakespeare’s The Tempest, “Tempest Fugit” is the perfect storyline to get Bruce Banner to face his innermost conflicts, which is what Ruffalo’s Hulk storylines have all been about.

The comic sees the Hulk tackle friends, enemies, frenemies, and a bunch of monsters on an island that is aptly called Monster Island. The twist ending is where it gets interesting: scientists are using this island to test a trippy, head-spinning new weapon that turns thoughts into reality, thus exploiting the worst fears of the person it’s used on in an ominously tangible way.

Future Imperfect

Maestro Hulk Comics Future Imperfect

Now that we have time travel in the MCU and Professor Hulk is more down to business after realizing that smashing stuff is superfluous, “Future Imperfect” would be an ideal story for a solo movie. In a future version of Earth, after a number of nuclear wars, all that’s left is a single city being ruled over by an elderly Hulk who has turned evil and taken on the name “the Maestro.”

In the comic, Rick Jones uses Doctor Doom’s time machine to get the present-day Hulk’s help, but in the movie, it could have something to do with the Avengers’ own time machine, which the Hulk himself built with the help of Scott Lang and Tony Stark.

The End

Marvel Hulk The End

At this point, we’re way past the chance to do an origin story with Mark Ruffalo’s Hulk. Edward Norton did a mediocre one before being replaced and Ruffalo has since carried the Hulk through a decade of his superhero career. So, if the solo movie is happening, an origin story is out. Why not flip it and do a Logan-style conclusion story instead? Rather than the beginning of his life as a superhero, let’s see the end of it.

That’s where “The End” comes in. It’s a haunting futuristic story that depicts Bruce Banner as the last man on Earth. A swarm of bugs attacks him and he turns into the Hulk. The Hulk regenerates and turns back into Banner. Then the bugs come back. This continues in an endless cycle. It’s a dark, chilling, surreal comic – but it could make an incredible film.

NEXT: Mark Ruffalo Wants His Hulk & Hugh Jackman's Wolverine To Interact On Screen