While it could be a while before Borderlands 4 becomes Gearbox’s focus, as Tiny Tina’s Wonderlands is still on the way, fans have a good idea of what to expect from the game’s story when it does arrive. The Director’s Cut DLC confirms that players will be searching for Lilith in the next mainline Borderlands game, with the Guardians also taking on a more prominent role in the narrative once again. However, there are plenty of other storylines the sequel could explore.

One of the biggest mysteries in the Borderlands universe is tied to the assassin Zer0. A fan favorite Borderlands character due to his stylish helmet, fancy sword, and unique personality trait of only speaking in Haiku, a dedicated fan base has been built around the Borderlands 2 Vault Hunter. However, his origins remain a mystery, with fans still having no idea what exactly Zer0 is. As such, Borderlands 4 should provide fans with this long-awaited answer.

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There are several things that make Zer0 interesting to Borderlands fans, and while there are a few theories regarding what exactly he is, many have agreed that he is not human. In Borderlands 2, Zer0 differs from the other Vault Hunters in the sense that he does not run out of breath when aiming snipers or sprinting. He also boasts some wildly skinny appendages, with many feeling that his body is too oddly shaped for a human to be hiding beneath the suit.

However, his similarities to the Borderlands 3 Vault Hunter FL4K have led to some even more intriguing discussions amongst the community. Both characters only boast four fingers on each hand, instantly making them different from humans. On top of this, they both contain a number in their name, something that has led fans to believe that there is a relation between the two characters. Both have access to cloaking technology as well, another intriguing similarity. With FL4K very clearly being a robot of some kind, and some clear features being shared, it can be assumed that Zer0 is a robot as well.

Outside of Gearbox acknowledging these fan theories and putting a bigger spotlight on the connection between Zer0 and FL4K, Borderlands 4 needs to explain what the pair's purpose is. Both characters are killers, with the Zer0 being an assassin and FL4K being a hunter. Still, they have wildly different personalities, as the animal-loving FL4K is nothing like the poetry-loving Zer0. At this point, learning why these deadly machines were created and who created them would be far more intriguing than the confirmation that they are, in fact, robots.

With the message from 0ne in Borderlands 2’s Son of Crawmerax Headhunter pack adding another layer to the mystery, as well as Katagawa’s use of Zer0-like armor, fans have had plenty to theorize about. With the questions regarding Zer0 having started back in 2012 with the release of Borderlands 2, and Borderlands 4’s release likely to be at least a few years away, fans will have been waiting for more information on Zer0 for over a decade. While there is fun to be had in keeping a mystery intact, most of the franchise's player base would likely agree that it has gone on long enough.

With both Zer0 and FL4K being sentient, but choosing to hunt down Vaults, perhaps there is something in their programming that calls them to this type of adventure. No matter what the reason ultimately was for their creation, or who was behind it, getting any insight into their origins would be thrilling. While it does not need to be the entire focus of Borderlands 4, spending a few story chapters on the Zer0 mystery would be wildly exciting for longtime fans of the franchise.

Borderlands 4 is rumored to be in development.

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