DC Comics is headlined by their flagship team, the Justice League of America. Created by Gardener Fox in The Brave and the Bold #28, the team combines the DCU's most popular and powerful heroes. Though the team's roster has changed over the years, the typical team carries most of if not all the original seven. These include Batman, Superman, Wonder Woman, the Flash, Aquaman, Martian Manhunter and Green Lantern.

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The JLA have joined with many heroes and even some villains over the years in order to overcome threats that required unlikely team-ups. Fans and the team themselves often know when these teams won't last, but it can be fun watching them play out. While many of these partnerships make sense, others are completely mismatched, and the League often joins with some untrustworthy characters.

10 John Constantine

John Constantine smiles and smokes a cigarette in DC Comics Vertigo

Constantine has the heart of a hero, but its largely buried beneath an exterior of self-loathing and cynicism. Constantine isn't a hero likely to team up with the Justice League out of the goodness of his heart. Rather, he's just as likely to look for an easy option out and leave the fighting to the pros.

Once Constantine is in the fight, he's usually a reliable hero to count on. However, he's also the sort to keep hidden plans to himself, or leave pressing issues to the last minute. Far from DC's worst hero, Constantine isn't exactly the most reliable one either.

9 Lobo

Lobo takes a break from fixing his bike in DC Comics.

Lobo's membership of the JLA has always been an uneasy one, owing to the antihero's bad attitude and selfish motivations. The punk rock bounty hunter of space, the "Main Man" Lobo is less interested in saving the world than he is in meeting women and getting into fights.

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Lobo has proven his lack of allegiance and outright maniacal personality by the fact that he personally wiped out his entire species himself. He may prove handy when things are at their worst, but Lobo's loyalty to the League aren't as important to him as his vices.

8 Etrigan The Demon

Etrigan The Demon DC Comics

Although Etrigan is typically a force for good in the DCU, the fact is his allegiances can go either way. In fact, one story saw him team up with Lobo in a bid to try and destroy the Earth. As a frequent member of the Justice League Dark, he's shown himself capable of great acts of heroism.

Etrigan is, ultimately, a demon from Hell. While he joins the heroes to take on true evil, he holds no real allegiances to the Justice League either. Were it not for Jason Blood's human half to keep the demon in check, he himself could be a menace within the DCU.

7 Batman

Batman standing in front of Gotham's ruins in No Man's Land cover art.

While technically a member - and occasional leader - of the Justice League, it's impossible to mention bad JLA allies without discussing Batman. Although he's every bit as heroic as his fellow Leaguers, as well as being the chief funder, he's been responsible for far too many team crises.

From keeping contingencies on the team that fell into the hands of Ra's al Ghul to unleashing Brother Eye, Batman can be as much trouble as help. By no means is he as volatile or nefarious as some of the team's other partnerships, but he does need to be kept in check.

6 Black Adam

Black Adam grants his fellow metahumans a powerup

Although Black Adam has recently been cast as an antihero, his history with the Justice League has been incredibly contentious. The ancient champion of Shazam, Black Adam spent most of his history as an outright villain. However, most modern stories have given him more depth.

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Black Adam is motivated by a combined warped sense of justice, loyalty to his people and self-preservation. Though he may join the Justice League in their quests, he also harbors villainous meta humans from the law in Kahndaq, and has the might to even challenge Superman - whom he has fought.

5 Maxwell Lord

DC Comics' Maxwell Lord smiling

During DeMatteis and Giffen's Justice League International, Maxwell Lord seized on the power vacuum left in the DCU after Crisis on Infinite Earths. He led the Justice League team itself, while under the influence of a nefarious super computer that wanted world domination.

Maxwell Lord has since grown into a full-fledged villain and is one of Wonder Woman's many mainstay villains. The billionaire businessman, Lord has incredible resources that almost rival those of Batman's. As a former leader of the JL, there have been fewer betrayals as big as Lord's.

4 Lex Luthor

Lex Luthor leads the supervillains in DC Comics

Many stories have seen Lex Luthor join the Justice League to take on villainy together. However, Luthor believes on a fundamental level that the meta humans with whom he works, especially Superman, are an existential threat to humanity's - and his own - dominance.

Readers and heroes alike rarely accept that Luthor is serious about a long-term shift to the side of good. He is typically treated with skepticism that he's covering up ulterior motives, and that is typically proven true. Luthor may help save the day, but he could be the next one trying to end it.

3 The US Government

Colonel Jonas and military officers DC Comics

The unity between the Justice League and world governments has always been fractious. However, due to their location within the United States, the US government serves as one of their natural allies, yet also a frequent adversary. This is especially true when competing interests clash.

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This relationship has been shown across DC media and can be traced back to surveillance and secret experiments - on both sides. For example, the Justice League have even gone so far as to intervene to stop the US military from possibly starting World War III.

2 Amanda Waller & The Suicide Squad

Amanda Waller Suicide Squad

Amanda Waller has leant her assistance to the Justice League when she judged it was in the interests of national security. The secretive and shady government operative in charge of the Suicide Squad doesn't trust the Justice League - and the feeling is mutual.

Waller and her Suicide Squad have reluctantly joined the JLA on missions to defend the United States or Earth itself. However, both she and the Suicide Squad view the League as allies of convenience. She's happy to keep tabs on the team and would go to war with them in a heartbeat if she felt she had to.

1 Joker

Joker Death Metal

While Joker is far from a normal ally to the Justice League, he has assisted them in previous stories. Joker's assistance to the JLA is always motivated by self-interest, and he rarely goes so far as to risk his own skin. However, there are exceptions.

In Scott Snyder and Greg Capullo's Metal saga, Joker teamed up with Batman in the eleventh hour to foil the Batman Who Laughs's plans. This was explained away as Joker not wanting to be upstaged by the nightmare Batman, as well as not wanting all existence to end. However, he's simply too chaotic and volatile to trust.

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