Craziest thing Master Chief has done

As one of the most iconic video game characters of all time, Master Chief has rightfully earned the respect of gamers around the world — as well the admiration of his canonical colleagues. The character has saved the universe more than once, and he's heralded as a hero in Halo's universe as a result, but the character hasn't always occupied the moral high ground. Players certainly have a biased view as a result of largely playing as Master Chief throughout the franchise, but the mythos surrounding Spartan-117 isn't as pristine as many gamers may believe it to be.

Whether it's laying waste to fellow members of the UNSC or almost inadvertently destroying every facet of organic life in the entire galaxy, Master Chief has his own fair share of horrific things from his past. This is sure to grow as future installments of the Halo franchise arrive, but for now, here's a look at the most terrible things Master Chief has ever done.

He murdered fellow soldiers

Being a soldier is one of the most dangerous jobs someone can hold, and that's especially true in the world of Halo. The United Nations Space Command (better known as the UNSC) is filled with the very best soldiers that humanity has to offer, but just because they're technically on the same side as Master Chief doesn't mean that John-117 has always treated them like allies. In one particular encounter, a confrontation between Master Chief and his fellow soldiers even turned deadly.

The novel Halo: The Fall of Reach finds Master Chief recovering from the augmentation surgery that helped to transform into a Spartan. At one point in the book, the young protagonist heads to the gym to try to bulk up and get back in fighting shape. As he's doing so, four ODST troopers walk into the gym to begin working out. This group turns confrontational, as they aren't aware that the man in the gym is part of the Spartan program. Things eventually escalate, until Master Chief ultimately pummels his UNSC comrades to a pulp — breaking bones and killing at least two of the ODST.

John-117 was a bully when he was a kid

It may be difficult to envision, but Master Chief wasn't always the battle-hardened badass that he's known as now. In fact, his journey to becoming the most notorious warrior in the galaxy began with John as a little kid. Prior to being stolen from his family as a child and replaced with an exact clone that would inevitably expire just a few weeks later, John exhibited tenacity on a whole other level than what children his age often showcase. This is most prominently shown during the
Halo: The Fall of Reach animated series, in which we find John at a playground engaging in a game of King of the Hill with some other children.

Unwilling to give any ground, he foregoes shoving other kids and resorts to kicking and headbutting to ensure that he remains on top. Not only is this sort of behavior problematic, but it's a clear sign that John was a bully. He didn't care who got in his way, as he simply resorted to violence if someone presented themselves as a threat to his goal. This mentality carries through to Master Chief in the games as well, but it's clear that a young John wasn't a pleasant person for any other kid to play with.

He left Sgt. Johnson to die

The events of Halo: Combat Evolved laid down what would eventually become one of the largest sci-fi franchises in the world, but just because it was the first foray into that universe doesn't mean that it was without its faults. For those who only played the games, one of the biggest problems in the transition from the first Halo title to Halo 2 was the fact that it's not really clear how the enigmatic Sergeant Johnson managed to get off the original Halo ring after Master Chief triggered it to self-destruct. 

While that question was eventually answered through media outside of the games, one of the more questionable aspects of this is just why Master Chief left Sergeant Johnson (and presumably many other UNSC soldiers) to die in a fiery explosion without so much as an escape plan or a gentle heads up.

It's clear in the game that Master Chief is focused on destroying the Halo ring no matter the cost, but given the relationship showcased between the two it's almost a little heartless that he is so willing to just let whoever happens to be on the ring go up in flames. Additionally, the game's secret, non-canonical ending even shows Sergeant Johnson hugging an Elite from the Covenant as the explosion consumes them both. That's some sort of terrible friendship with Master Chief.

He could have helped make humans immune to the flood

Sgt. Johnson manages to survive his encounter with the parasitic entities known as the Flood in Halo: Combat Evolved is because he's immune. Not knowing how or why, Master Chief learns that Johnson may hold the key to making UNSC forces (and all of humanity) immune to the Flood. Despite this, he opts against informing anyone about Johnson's apparent superpower for fear that the government will ultimately dissect him to learn more his invulnerability to the galactic menace.

Perhaps this decision was based on the guilt he felt after he seemingly left Sgt. Johnson to expire on the original Halo ring, but this decision cost other soldiers their lives later on. Eventually it's discovered that Johnson had gone through a similar process to Master Chief which made him immune to the Flood.

Master Chief almost absent-mindedly wiped out all organic life in the universe

Many of Master Chief's terrible decisions can be traced back to the first Halo game, but the fact that the Spartan almost wiped out all organic life in the galaxy easily stands out as the worst blunder. During the events of Halo: Combat Evolved, Master Chief encounters an A.I. character known as 343 Guilty Spark. The character claims to be an ally programmed by the Forerunners, and babbles on during a later mission in the game about the protocol that he must initiate since the Flood has escaped from the Halo ring. This protocol in particular involves wiping out all organic life in order to remove the food source of the Flood and prevent the spread of the monstrous race.

Master Chief, who is a man of few words, displays selective hearing while 343 Guilty Spark spills the beans on his plan. Since Cortana isn't present during this (having instead uploaded herself into the Forerunner computer system to aid Chief), John-117 simply follows the commands of the floating orb. As he's about to activate 343 Guilty Spark's failsafe plan, however, Cortana springs from the control board and is reunited with Chief before furiously scolding the Spartan for almost killing everyone. That's right — Master Chief and his inability to pay attention could have just as easily been the worst thing to ever happen to the human race, if it weren't for the last-minute intervention of Cortana.

He allowed Cortana to go rogue

It's no secret that Master Chief and Cortana have a very unique relationship. Truth be told, no one really knows how deep it runs — perhaps fans never will — but the partnership that they share was never meant to last. Artificial intelligence beings created by the UNSC like Cortana begin to enter a terminal phase known as Rampancy after existing for approximately seven years. What happens is that the A.I. essentially thinks itself to death, but in the process the artificial being reaches a state of mind where it grows tired of its creators and begins seeking godlike power. Before this can happen, the UNSC is forced to retire and dispose of them so that they don't turn against them. Cortana actually reaches this point during the events of Halo 4... but she's never retired.

When the official orders come to have Cortana decommissioned as a result of her Rampancy, Master Chief directly ignores them to the face of a superior officer. Despite the fact that Cortana is beginning to lose her mind, Master Chief can't bring himself to turn his back on his longtime companion. While an admirable decision in the moment, this eventually leads to Cortana becoming a threat in Halo 5. In fact, she rallies almost all of the UNSC's other A.I. under her as she tries to gain control of the universe. This decision to keep her around still has ramifications as gamers prepare for Halo Infinite, and is sure to play into that narrative in a meaningful way. Still, it's clear that the end result of Master Chief's decision has had and will continue to have horrifying repercussions.

Master Chief Goes AWOL

After learning that Cortana is alive following the events of Halo 4, Master Chief leaves the UNSC (along with three members of his longtime canonical Spartan crew, Blue Team) in order to track her down and rescue her. In choosing to abandon the UNSC and pursue the signs of his friend's survival, Master Chief goes AWOL. This results in Spartan Locke and Fireteam Osiris being assigned to bring in Blue Team so that they can be reprimanded. John-117 and Locke even have a full-on brawl as Master Chief tries to evade the other team and find Cortana.

As it turns out, the distress calls being sent by Cortana were a trap so that Cortana could "protect" Chief and his friends as she alters the world around them. Eventually, Blue Team is saved by Fireteam Osiris, but the damage is done, and Cortana has already begun her plan to conquer the universe. Going after a friend in the first place is noble in and of itself, but the fact that Master Chief ignored orders to allow another Spartan team to pursue intel on Cortana ended up being the most terrible choice he could have made in that scenario — not just for him, but for the entire galaxy.