It's official -- "Guardians of the Galaxy" is the latest of Marvel's ever-growing number of sub-franchises! The intergalactic team of a-holes now has a sequel rocketing into theaters in 2017, a fact that Marvel announced during Comic-Con International in San Diego. Yeah, that's right -- the first "Guardians" film instilled so much confidence in the studio that they greenlit and announced a sequel before the first film even opened in theaters.

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So having seen the first "Guardians" blockbuster-in-the-making and knowing that another interstellar epic is coming our way, is there any way to guess which heroes we'll see join up with the team on the next go-round? If anything, "Avengers: Age of Ultron" has shown that Marvel Studios isn't afraid to build-up a team's roster significantly with each installment. Who will be the Scarlet Witch, Quicksilver and Vision of "Guardians of the Galaxy 2?" Read ahead -- and beware slight spoilers -- to see our picks!

MantisThis iteration of the Guardians kicked off in 2007's confusingly named "Annihilation: Conquest - Star-Lord" limited series, and there are only two other character that appeared in that series and the following "Guardians" ongoing that don't appear on the big screen. One of them is Mantis, a human raised by the Kree's Priests of Pama to be a skilled martial artist. She also has a wide array of mental powers and precognitive abilities at her disposal, which allowed her to be the voice of logic on the team. "Guardians" already has two green ass-kickers on their roster, but Mantis could easily fill a Spock-like role on the good ship Milano.

MoondragonAs with any sequel, we really hope the Guardians' backstories get thoroughly explored. The movie could bring Moondragon in if they want to give the emotionally blunt Drax something big to react to. Spoiler alert, Moondragon is Drax's daughter -- yeah, the dead daughter that inspired him to go on a vengeance quest. Movie Drax is apparently an alien, and the name he gave for his daughter was definitely not Heather (Moondragon's real name). Still, a reimagined Moondragon could appear, possibly with a green and red makeover similar to her father's.

BugConsidering the great success the "Guardians" animators had with Groot and Rocket -- quite possibly the first time a tree and/or raccoon have made you cry that many tears in a film -- we really want to see what they'd do with Bug. Originally a member of the licensed comic "Micronauts," Bug survived the dissolution of the license because he was an original character created by Marvel specifically for the series. He disappeared for a while before returning alongside Mantis in the "Annihilation: Conquest - Star-Lord" series. He then became a mainstay of the Guardians, appearing as recently as Brian Michael Bendis' relaunch of the team in 2012's "Avengers Assemble." Despite being a twitchy guy with creepy insect powers, Bug's good-natured attitude makes him one of the team's more relatable aliens.

Adam WarlockMarvel's answer to "Jesus Christ Superstar" -- no, seriously -- this artificially created golden not-quite-a-god broke free of his Earthly prison to soar through outer space as a force for cosmic good. He spent most of his time clashing with the Universal Church of Truth, a cult-like organization devoted to Magus, a villain that turned out to be the completely evil future version of Adam Warlock. Comics! Creator Jim Starlin got a hold of Warlock in the mid-'70s and teamed him up with two of his other creations, Drax and Gamora. The character was pretty popular in the '90s; he headlined his own team book, which formed the center of a number of "Infinity"-titled events. With most of his allies and enemies already introduced into the MCU, adding Adam wouldn't be that hard.

Phyla-VellIt might be hard to add Phyla-Vell, though. She is the artificially created daughter of the original Marvel Comics Captain Marvel that only popped into existence after her artificially created brother Genis-Vell destroyed and recreated all of reality. So... she's got a complicated history going against her. But you know who else's history has a head-scratching number of switcheroos, retcons and fake-outs? Thor -- and Marvel Studios streamlined his origin and made it work. The same can be done for Phyla-Vell. Just make her a member of the Kree and the daughter of a big-time military hero named Mar-Vell. Maybe even include a throwaway line about Mar-Vell having been away on mission on a faraway planet for decades (*cough*Earth*cough*). Phyla could use her presumed-dead dad as fuel for her own heroic journey, as she inherits his powerful quantum bands and takes to the stars, trying to repair the damage Ronan did to her Kree people's name. Having a member of the Kree on the Guardians team could also provide for some Worf-on-the-Enterprise-style tension. Plus, Phyla-Vell and Moondragon are one of the few lesbian couples in mainstream super hero comics. They need to be in a movie, as soon as possible.