Following early skepticism among critics and fans, "Marvel's Agents of S.H.I.E.L.D." ended its inaugural season strong, with a super-charged, cybernetic Bill Paxton and resolution to the resurrected Agent Coulson's (Clark Gregg) season-long existential crisis.

Beyond Paxton's John Garrett, the first season of "Agents of S.H.I.E.L.D." introduced several more established characters to the Marvel Cinematic Universe, including Victoria Hand, Dr. Franklin Hall (Graviton), Donnie Gill (Blizzard) and, most notably, Deathlok.

RELATED: Loeb & Bell Unpack "Agents of SHIELD" Season Finale and Tease What's Next

The second season -- still a few months away -- will undoubtedly continue to explore Marvel's roster of characters, with comic book heroes and villains that could be potentially taken from multiple corners of the Marvel Universe. Despite Marvel Studios' many, many film projects, there are any number of Deathlok-level names who could theoretically be introduced to Coulson's crew, readymade characters just waiting to make an impact. Here are just a few speculative additions to "Agents of S.H.I.E.L.D." season two.

The Patriot

The inclusion of Agent Triplett, grandson of one of the Howling Commandos (first seen onscreen in "Captain American: The First Avenger"), introduced the idea of legacy heroes to the world of "Agents of S.H.I.E.L.D." The Patriot carries the legacy of two Golden Age heroes: Jeff Mace, the first hero to use the name the Patriot, and Isaiah Bradley, the first man to take on the mantle of Captain America. Either one could potentially appear on ABC's other Marvel TV series, the newly greenlit "Agent Carter," which also opens the door to a connection between both series if Marvel raids their library and drafts the modern day Patriot, Eli Bradley, into S.H.I.E.L.D. In the comics, Eli is a founding member of the Young Avengers and could be used to show just how deeply the Marvel Universe has been affected by Captain America. With classic Marvel U material coming to television via "Agent Carter," "Agents of S.H.I.E.L.D." will need a hero whose story connects both eras and extends the legacy of S.H.I.E.L.D. as an organization. The Patriot can be that hero, and he could even serve as a harbinger for the next generation of Avengers.

Balder the Brave

Fans were treated to guest spots from two Asgardians in the first season of "Agents of S.H.I.E.L.D." -- the heroic Lady Sif and the evil manipulator Lorelei. What's stopping the series from adding a permanent cast member from the Golden Realm? Balder the Brave, Asgard's most noble hero, has been conspicuously absent from the "Thor" films thus far. As a huge presence across many different eras of "Thor," it would be a shame if Balder never played a similar part in the Marvel Cinematic Universe. As a permanent member of the "S.H.I.E.L.D." cast, Balder could keep audiences abreast of the goings on in Asgard between "Thor" films and add an element of the fantastic to the largely grounded series.

Elsa Bloodstone

Fans have been teased with rumors of a "Doctor Strange" film for years, and even with Scott Derrickson announced earlier this week as the film's director, there's still no word on when exactly magic is coming to the Marvel Cinematic Universe. Maybe the mystic side of the world can first be introduced in "Agents of S.H.I.E.L.D." through Elsa Bloodstone. We know Joss Whedon has a history of centering shows around tough young women who battle the supernatural, and Elsa would fit very comfortable in his wheelhouse. She's a tough as nails monster fighter who would fit right into the show's dynamic. Agent Ward will need to be replaced, and Elsa could hold her own with anyone -- monster or otherwise. There are legions of monsters and demons in the Marvel Universe, and until Dr. Stephen Strange enters the scene, someone has to fight them. Elsa Bloodstone could be the entry-level character that makes the Marvel Cinematic Universe a little more magical -- and a little more monstrous.

Eric O'Grady

Eric O'Grady could be just the character to create perfect synergy between Marvel's films and television efforts. Unless you live in an anthill, you know "Ant-Man" is coming to theaters 2015 -- provided Marvel can sign up a director to replace Edgar Wright. Crass, lazy and generally obnoxious, Eric O'Grady is one of the worst agents S.H.I.E.L.D. has ever employed, and is best known to comic readers as the Irredeemable Ant-Man. O'Grady could be introduced in season 2 as an operative Coulson reluctantly adds to his team who then become an immoral version of Ant-Man in the post-Scott Lang world of season 3. Rogue operatives are nothing new for Coulson, but O'Grady's personality and technology could make him quite the foil the team and the resurgent agency. The character is like "Family Guy's "Quagmire with a badge, and after he gets his hands on the Ant-Man tech O'Grady could prove to be quite the wildcard for the series.

Michael Collins (Deathlok)

The saga of Deathlok doesn't have to end with Michael Peterson. Actor J. August Richards did an exemplary job introducing and making audiences care about his character, the first man to bear the mantle and curse of Deathlok, but as comic fans know, Peterson wasn't the only man to ever bear the moniker. Michael Collins was a pacifist who paradoxically became a Deathlok; a man with a peaceful heart trapped in the body of the ultimate killing machine. What if Cybertek attempts to create another Deathlok to bring down Peterson? The tragic dichotomy of Collins would make for some intriguing television, especially now that mainstream audiences are more than familiar with the concept of Deathlok. Adding a second Deathlok to the series could also foreshadow the tragic future of the first comic book Deathlok, Luther Manning, as well as open the door for the new Deathlok being introduced in next week's "Original Sins" #1.

Richards "Wants Redemption" for Deathlok on "Agents of SHIELD"

Jennifer Walters

Let's face it: Fans want a live action She-Hulk. Fans of John Byrne, Dan Slott, and Charles Soule's take on the character know that there is a depth to Jennifer Walters that would be perfect for film or television. And with S.H.I.E.L.D. in disarray, you just know Coulson and his crew will likely need some sort of legal representation at some point. Matt Murdock's going to be busy in Hell's Kitchen, so let's turn to the other big-name Marvel U attorney, and tighten the bond with the Avengers films at the same time. By accepting a job that puts her on the front lines, Jen could very easily end up requiring that fateful blood transfusion from cousin Bruce, introducing the fan-favorite character to the world outside of comics. And by getting to know her before she goes big and green, we'd be getting a new, fresh take on a character who's been around for decades.

Quasar

As seen in the first season, there is apparently an alien presence on Earth beyond the established Chitauri invaders. Earth will need a Cosmic Protector to keep those alien incursions at bay, especially with Thanos out there, casting his eye toward our home planet. Agents Fitz and Simmons already made mention of studying under Professor Vaughn at the S.H.I.E.L.D. Academy, and other elements of the character's comics history are in place (Project Pegasus, anyone?), so it would be a simple matter to introduce Fitz/Simmons' former mentor and gift him with Quasar's signature Nega Bands. Let's face it, villains like Thanos, the Collector, Ronan the Accuser and Nebula are out there, along with Dark Elves, Chitauri, Kree and countless more potentially aggressive alien species. Earth very obviously needs a hero unafraid to be the thin line of protection between his world and outer space.

Carol Danvers

Before she was Ms. Marvel, before she was Binary, before she was Captain Marvel, Carol Danvers was a high ranking officer in the U.S. Air Force. In other words, she's perfect S.H.I.E.L.D. material. Establishing Carol as an agent can make her eventual rise to an Avenger that much more powerful. Perhaps she's another of Coulson and May's longtime colleagues, or even a one-time protege, re-enlisted by Coulson's now on-the-run team. Many fans are postulating that the alien blood currently flowing in Coulson and Skye's veins is Kree, and if that doesn't perfectly dovetail into Carol Danvers' heroic origin, we'll trade in our S.H.I.E.L.D. ID card.

Punisher

It's not a matter of if Frank Castle will appear in the Marvel Cinematic Universe; it's a matter of when, so why not give him his introduction on "Agents of S.H.I.E.L.D.?" Whether a new ally or old colleague of Agent Coulson or May, Frank Castle could be a replacement for the traitorous Agent Ward, a tactical genius who sets the standard for the new S.H.I.E.L.D. led by Phil Coulson. By taking time to establish Castle as a man and a soldier, when the unthinkable happens and the Punisher is born, the character could be imbued with some of the depth Garth Ennis gave him rather than being a shallow, one-note, human meat grinder.

Shang-Chi

Even in the less-than-great episodes, the fight choreography on "Agents of S.H.I.E.L.D." was excellent. Well, let's up that ante. Shang-Chi, the Master of Kung-Fu, a man on the run from his past and the sins of his family would be a great street-level addition to the show's cast. Shang-Chi could start as a potential replacement for Ward, before exploring some of the more intriguing elements of his comic book backstory. Marvel would probably want to avoid the racial and legal pitfalls of actually making Shang-Chi's father Fu Manchu, but that doesn't mean dear old dad can't be a high-level HYDRA Agent, or maybe a threat tied to the early days of S.H.I.E.L.D. and Peggy Carter. With Iron Fist ready to make his Netflix debut, it's time for Shang-Chi to get in on the Kung Fu fun as the latest "Agents of S.H.I.E.L.D." recruit.