From Halopedia, the Halo wiki
Become is a marketing campaign for Halo Infinite. It features the word "Become" as a tagline, signifying that players are assuming the role of the Master Chief and becoming a hero in the Halo Infinite campaign.
- Step Inside - A trailer showing the creation of the MJOLNIR Powered Assault Armor (GEN3) Mark VI.
- UNSC Archives - This is a sub-set of trailers tied to the Become campaign. They are intended to depict stories not yet depicted in the Halo universe.
- Unspoken - This trailer depicted the events following the recovery of Kig-Yar point defense gauntlets by Chris Preston and David Dominguez in 2526, in which Preston, who survived the encounter with the Covenant, recorded a message for Dominguez's parents. 
- Project Magnes - This trailer depicted the video logs recorded by the civilian engineer who developed the Grappleshot under the name "Project MAGNES", interjected by scenes of the engineer talking to her daughter on a video call.
- Lightbringers - This trailer depicted a group of colonial miners volunteered to extract an ore for MJOLNIR's exoskeleton, on a bombarded UNSC excavation site.
- Carry On - This trailer depicted John-117 combating a group of Banished Jiralhanae led by Tovarus on the surface of Installation 07.
- Forever We Fight - This trailer depicted many heroes throughout human history: a shepherd defending his flock from a pack of hyenas, a civilian woman taking up arms to defend a wounded soldier during World War II, a first responder diving into a turbulent ocean to rescue someone from drowning, a scientist testing the Shaw-Fujikawa Translight Engine, a UNSC Marine saving a pilot from the wreckage of their AV-14 Hornet, and finally John-117 fighting for humanity on Installation 07.
The Become campaign was created by 215 McCann, the San Francisco-based advertising agency that previously created the Believe campaign for Halo 3 and the Hunt the Truth campaign for Halo 5: Guardians. Brad Meyers, the creative director at 215 McCann, viewed the Become campaign as a spiritual successor to Believe. Furthermore, Meyers directly cited the soldier testimonials from Believe as direct inspiration for the UNSC Archives series. However, the creative team shifted the focus away from John-117 being the central figure and hero to believe in, because they have observed that an increased interest in anti-heroes in popular culture. Instead, they sought out to focus on acts of heroism behind the Mjolnir armor, and tell viewers that they can be the hero they wish to be in the real world.
- Twitter, Aaron Greenberg (@aarongreenberg): "The world needs heroes right now as our Become Campaign starts ramping up in anticipation of launch. Escharum and your role at Master Chief giving me all the feels."
- 215 McCann, Work Detail - Halo Infinite - Become (Retrieved on Nov 6, 2021) [archive]
- Twitter, Halo (@Halo): "UNSC Archives accessed. Contained within are the untold stories of humanity and heroism behind the Master Chief. Stay tuned for further transmissions." (Retrieved on Nov 2, 2021) [archive]
- YouTube - HALO, UNSC Archives - Unspoken: "Assigned to a freighter escaping the destruction of Harvest, two Marines confiscated alien energy shields while defending passengers from an enemy boarding assault. Their heroics led to a technological breakthrough that accelerated the development of the Master Chief's defense system." (Retrieved on Nov 2, 2021)
- YouTube - HALO, Halo Infinite | UNSC Archives - Project Magnes: "Discover the untold story behind the Master Chief's newest upgrade, the Grappleshot, and the civilian engineer who changed Spartan 117's arsenal forever." (Retrieved on Nov 6, 2021)
- YouTube - HALO, Halo Infinite | UNSC Archives - Lightbringers (Retrieved on Nov 13, 2021)
- YouTube - HALO, Halo Infinite | Carry On (Retrieved on Nov 28, 2021)
- YouTube - HALO, Halo Infinite | Forever We Fight (Retrieved on Nov 28, 2021)
- 215 McCann, Work Detail - Halo Infinite - UNSC Archives (Retrieved on Nov 6, 2021) [archive]
- 215 McCann, Work Detail - Halo 3 - Believe (Retrieved on Nov 6, 2021) [archive]
- 215 McCann, Work Detail - Halo 5: Guardians - Hunt the Truth (Retrieved on Nov 6, 2021) [archive]
- Adweek, How Halo Infinite's Marketing Is Building on the Franchise's Iconic, Immersive Advertising (Retrieved on Nov 6, 2021) [archive]