OK, so things might be looking a little bleak for Earth's Mightiest Heroes' Marvel Cinematic Universe incarnation as of this very moment. The effects of 2018's Avengers: Infinity War are setting in, we're about to be introduced to Brie Larson's Captain Marvel and Avengers: Endgame is on the horizon. While things will certainly turn in favor of the Avengers by the end of things, we're not so sure about the status quo for the MCU when the credits roll on Endgame. We also don't know what the Avengers team makeup is gonna look like, or where Marvel wants to go with the future of the MCU.

Could Captain Marvel be setting up a potential "Secret Invasion"? Will the introduction of 20th Century Fox's X-Men and Fantastic Four properties bring us to a "Secret Wars" series of films? Maybe, maybe not. Things like the Quantum Realm, sorcery, hell and the other realms have yet to be explored, which means everything is really up in the air as far as characters and films go after Endgame. We know there will be sequels to Spider-Man, Black Panther, Guardians of the Galaxy and Doctor Strange, as well as a Black Widow film, but what's next? Could the Hulk lead to a Red Hulk or She-Hulk debut? Will the Quantum Realm introduce us to Black Knight? What about young heroes like Ironheart, Ms. Marvel or Nova? Here are some Avengers we think could make their debut and a few we imagine Marvel will be keeping on the back-est of back-burners.

20 COULD SEE: BLACK KNIGHT

Black Knight

Perhaps one of the most interesting potential additions to Phase Four of the Marvel Cinematic Universe is Dane Whitman, probably better known as Black Knight. If the MCU travels further into its weird territory, then Black Knight could be the perfect way to explore that, especially if the theories that the character is somehow tied Ant-Man and the Wasp's Quantum Realm are to be believed.

Plus, we could get a hilarious story about a modern day man that gets sort of sent back in time and does a whole King Arthur fantasy thing. Yeah, that might spice things up a bit in the MCU.

19 NEVER: HERCULES

Hercules from Marvel Comics preparing for battle in a destroyed city

Of all of the "nevers" on this list, Hercules might be the toughest to accept. Not only is he a lovable, super positive superhero, but he also adds an incredible amount of depth to the gods in the Marvel Universe.

However, between Disney's own stake in the Hercules name and the fact that Thor, in a lot of ways, in currently checking all of Hercules' boxes in the Marvel Cinematic Universe, we just don't really see a place for this guy in the next few years of films. However, if there's a Hercules and Amadeus Cho show or movie in the cards, we certainly wouldn't say no to that.

18 COULD SEE: MS. MARVEL

Ms Marvel Kamala Khan

Honestly, we're half expecting to see the base set for Kamala Khan in the upcoming Captain Marvel, but even if she doesn't, we bet the hero of Jersey City will make an appearance in the next few years of the Marvel Cinematic Universe. Not only is Kamala Khan incredibly popular, but she's incredibly important to the legacy of Captain Marvel, the acceptance of Inhumans in the Marvel Universe and a torch-bearer for a new generation of heroes that include Miles Morales and Sam Alexander.

On top of all of that, Ms. Marvel brings much-needed representation to the MCU, something that is important if the MCU is to grow with the fans that support it.

17 NEVER: ARES

Ares

Too many gods and warriors running about? Well, how about Ares? Well, not exactly. We can't imagine this Dark Avengers making an appearance in the Marvel Cinematic Universe even if that squad comes into play during the aftermath of Endgame or in the run-up to a potential "Secret Invasion." Not only that, but Ares has already been a major player in DC's film universe in Wonder Woman, so things might get too murky there.

On top of that, Ares doesn't come close to the potential of other godlike beings in the MCU, like the already introduced Valkyrie or Hela -- not to mention players like Beta Ray Bill that we haven't even really seen yet.

16 COULD SEE: SHE-HULK

She-Hulk

With the solo film rights to Hulk seemingly up in the air, what better way for Marvel to retake the mindshare of a gamma-irradiated hero than by introducing the incredible Jennifer Walters as She-Hulk. Not only could she offer a different dynamic to the childlike Banner Hulk, but a film for herself could play like a legal drama, just with a lot more kicking butt and saving the world outside of the courtroom.

Jennifer Walters is too good of a character to not bring into the fold as Phase Four ramps up, and it would be a nice break from the Hulk that we already have. Not that we don't like him, but sometimes different can be even better!

15 NEVER: MARVEL BOY

Marvel Boy dual wielding assault rifles from Marvel Comics

The Kree superstar Marvel Boy could very easily slot into a number of upcoming films, whether its Captain Marvel or a future Guardians of the Galaxy flick, but we have a feeling we won't be seeing this bonafide Young Avenger any time soon.

Why? Well, Marvel already has plenty of Kree influences to worry about in Phase Four, whether it's the Supreme Intelligence, Captain Marvel herself or the number of Inhumans running about in Agents of S.H.I.E.L.D.  It might be a little too soon to introduce Noh-Varr to the MCU, though we can't say we're totally against it should Marvel go the Young Avengers route.

14 COULD SEE: NAMOR

Between the success of Warner Bros.' Aquaman and the multitude of possibilities that Phase Four bring to the Marvel Cinematic Universe, we could see Namor the Sub-Mariner playing a huge role in what comes next.

The former Invader could appear in a number of ways, in a film like Black Panther 2, as a solo-starring hero to introduce mutants to the MCU or even as a wallflower addition to the number of super teams now in play in the MCU. Our number one pick? That we see Namor show up as a villain in Black Panther 2 before a potential heel turn to the light.

13 NEVER: RED HULK

Red Hulk Sending Cars Flying

For the sake of argument, we're going to focus here on the Red Hulk that is actually General Thunderbolt Ross. While Ross is firmly established in the Marvel Cinematic Universe already, we can't exactly imagine him turning into a red raging Hulk monster and trouncing some of the Avengers. However, Ross may come into play if theories about an MCU Thunderbolts team to come to fruition during Phase Four.

Now, another Red Hulk could probably make sense, maybe even as an extension of Ross's previous obsession with Banner and his gamma experiments. The Thunderbolts, though, that's a much more interesting prospect for everyone's least favorite general.

12 COULD SEE: MOON KNIGHT

Moon-Knight

We already know that Marvel Studios is exploring its options when it comes to the Marvel Knight Moon Knight. Marc Spector could, in a sense, help bridge the gap between most of the defunct Marvel Cinematic Universe Netflix shows. Moon Knight is a ground level protector of New York, but he clearly has the abilities and history to run with the best of the best, and could easily bring Luke Cage, Daredevil and the like into the silver screen.

Between the potential there and the genuine cool factor and mental health positivity that Moon Knight brings, we'd say this is probably a safe bet for Phase Four, if not shortly after.

11 NEVER: AGENT VENOM

The potential of Agent Venom in the Marvel Cinematic Universe really just rests on the universe's Flash Thompson, who is currently a teenager. And though this timing does lock Agent Venom out of Phase Four of the MCU, it doesn't halt the potential of the Secret Avenger showing up in Sony's separate Spider-Man universe films, especially since Tom Hardy fits the bill a lot more than the younger MCU Flash does.

It would take a bit of twisting, but it'd make sense. Nevertheless, the Secret Avenger Agent Venom has a low chance of appearing any time soon in the MCU.

10 COULD SEE: SPIDER-WOMAN

Spider-woman maleev

While Sony is partnering with Marvel Studios on the Tom Holland Spider-Man films, there's a chance that a Spider-Woman film could be totally in Disney's hands. Why? Well, Jessica Drew is actually quite different than Peter Parker, and her powers and history deal with everything from Hydra, Skrulls and experimentation to brainwashing and S.H.I.E.L.D. agent hijinks. She would be the perfect addition to a growing MCU.

On top of that, her more recent comics have delved into things like motherhood and friendship all while managing the life of a top tier superhero. That's something that could bring an interest layer to the films.

9 NEVER: DOOMBOTS

Doctor Doom Doombots

While Victor Von Doom could certainly make an appearance in the Marvel Cinematic Universe in the coming years, we doubt one of his Doombots will heel turn and come to the side of the light during any of that time. The Avengers' Doombot is one of those things that feels quirky in just the right way to the comics, but might not offer too much to audiences deep into the MCU.

Though, we bet there are plenty of Doombots in whatever the Fantastic Four looks like in the MCU. After all, they're such an integral part to Doctor Doom's ego that we wouldn't want to miss them in a potentially perfect live-action take on the character.

8 COULD SEE: CAPTAIN BRITAIN

Captain Britain Alan Davis

We already have Captain America, so why not? Not only would Captain Britain be a stellar addition to the Marvel Cinematic Universe, but he offers a totally different history than even Steve Rogers. On top of that, the appearance of Brian Braddock has been rumored in the MCU for a bit now, we're just sort of waiting for the right place to assume he'll show up in.

As part of an Avengers squad, he could continue to help prove that the team is a global peacekeeping force. Plus, there's something really awesome about his costume, and we'd love to see what that would look like in live action.

7 NEVER: HYPERION

Marvel's Hyperion standing among the flames in Marvel Comics

There are plenty of pseudo-Supermen in the Marvel Universe, but we're not so sure Hyperion would be the one to pull from the comics and bring into live-action. His power set a motif are fairly similar to Kal-El's, which could just end up confusing audiences.

We know Marvel wants to expand its universe even more, but with the potential from the Fantastic Four and X-Men on the horizon, Hyperion probably isn't in the cards. However, we'd love to see a bearded Hyperion pair up with Thor at the end of the universe in a potential "Secret Wars" film. Maybe one day.

6 COULD SEE: WOLVERINE

For fans eagerly awaiting the arrival of the X-Men to the Marvel Cinematic Universes, chances are that for many, it's for one guy: Wolverine. And sure, it might be nigh impossible to replicate the success that Hugh Jackman found in the role, quite literally defining superhero films since the early 2000s, but that doesn't mean Marvel shouldn't try. If there's a member of the X-Men that's going to join the Avengers in Phase Four, it will probably be Wolverine.

And honestly, he's one of the last missing pieces to make the Avengers films feel like they've reached a peak. This would be further proof at how far Marvel Studios has gone in reaching its goals.

5 NEVER: STARBRAND & NIGHTMASK

Never Should Have Been Avengers Starbrand Nightmask

For the sake of this argument, we'll use the more recent versions of the cosmic heroes Starbrand and Nightmask. While their solo comic and additional exploits leading up to Marvel's "Secret Wars" were kind of amazing, we feel like these two would have a hard time grooving with the current state of the Marvel Cinematic Universe.

Sure, there's reference to be had in a future Guardians of the Galaxy or The Eternals films, but we're not sure the MCU is ready for them. In addition, Starbrand's origin in this sense is pretty dark, and might be a bit too much for some. It's honestly more like accidental villainy than anything.

4 COULD SEE: SHANG-CHI

Shang Chi Master of Kung Fu

While not 100% confirmed, we're pretty sure that the Master of Kung Fu, Shang-Chi, will be making his Marvel Cinematic Universe appearance sometime during the Phase Four films. Not only could a martial arts-focused film be killer as part of the Marvel Studios lineup, but Shang-Chi is a mystical, layered character that would bring much-needed representation to the MCU.

Will he kick it with the Avengers during that time, though? We'd have to imagine so, especially as Marvel prepares to retire the old guard and introduce a new generation of heroes to film audiences. One can only hope Shang-Chi is a part of that.

3 NEVER: SABRETOOTH

As the Marvel Cinematic Universe kicks into Phase Four, there's a chance bits and pieces of 20th Century Fox's Marvel properties will work their way into the main set of films. And sure, the X-Men, Fantastic Four and more are all possibilities, but even if these super teams come to pass, Victor Creed probably won't show up in time for Phase Four. Not to mention he certainly wouldn't appear as a hero.

Victor Creed's stint as an Avenger came as part of the Avengers Unity Squad, and it was a nice heroic take on the character after "AXIS" and before the return of Wolverine.

2 COULD SEE: SENTRY

Marvel Comics' The Sentry looking down imperiously

As the Marvel Cinematic Universe reels from whatever status quo Endgame sets for it comes April, there's plenty of potential to look forward to. And one of those possibilities is The Sentry. Not only is Bob Reynolds a Superman-adjacent hero, but he's also got a dark history of baggage that could certainly make an interesting solo film, if not set him up as a more grounded "villain" for the Avengers to face.

Now, if Asgard finds a new home on Earth and we start to get a bit of "Siege" in our Marvel movies, then, well, audiences are in for an interesting play from Sentry.

1 NEVER: DEADPOOL

This isn't so much about the certainty that Deadpool won't make an appearance in the Avengers films from here on out, but it'll be a hard sell to put a character so focused on mature themes into the mold with the rest of Earth's Mightiest Heroes. And even though there is a slim chance the future will bring Deadpool into the fold, it probably won't happen in Phase Four of the MCU.

With the 20th Century Fox deal in its final stages, it could still be years before we see any fruits of the purchase make their way to Marvel's established cinematic universe. But when Deadpool does arrive, it'll surely be something.