Marvel's Agents of S.H.I.E.L.D. season 6's new villain Sarge is definitely not from Earth - but the doppelganger is still somehow linked to the late Phil Coulson. In last week's season premiere, "Missing Pieces", Sarge arrived as the leader of a dangerous squad consisting of Snowflake, Pax, and Jaco. Driving a massive armored 18-wheeler truck with a cloaking ability, Sarge arrived on Earth through a portal at the Museum of Natural History and attacked S.H.I.E.L.D., killing Agent Fox in cold blood. When Fox identified himself as an Agent of S.H.I.E.L.D., Sarge quipped, "Never heard of it." So where is Sarge from and what's his connection to Phil Coulson?
Introduced in 2008's Iron Man, Agent Coulson was a mainstay of the MCU movies until Loki killed him in The Avengers. However, Coulson was resurrected by Project T.A.H.I.T.I. using Kree technology and he was placed in charge of his own team of S.H.I.E.L.D. Agents. After S.H.I.E.L.D. was exposed as Hydra and collapsed, Coulson's team essentially became S.H.I.E.L.D. and he rose to become Director. In Agents of S.H.I.E.L.D. season 4, Coulson merged with Ghost Rider, but the Spirit of Vengeance's magic essentially burned through the Kree tech that was keeping him alive. The Director was slowly dying and he finally succumbed at the end of season 5 with his love Melinda May by his side - fittingly, in Tahiti. But May swears that Coulson died one year before the events of Agents of S.H.I.E.L.D. season 6, so taking her word as ironclad, who and what is Sarge?
This week's episode, "Window of Opportunity", opens with Sarge and his team robbing an Ohio convenience store for supplies, but their dialogue dropped numerous clues about their true origins. They never drank a Slurpee before, calling it "sugar water", and they were surprised to see "combustion weapons" (a shotgun) and "paper money". Pax remarked, "This rock has everything!" and later, inside their truck/mobile headquarters, Jaco wore an oxygen mask because he hadn't breathed his "home atmosphere" in months. Although they arrived via portals through ley lines and not a spaceship, all of their comments point to Sarge's team having an extraterrestrial origin, including their search for P-E-Gs, which are piezoelectric gems, crystals that are naturally polarized and can generate an electric charge under applied mechanical pressure. But there's even more mystery when it comes to Sarge himself.
According to DNA samples of Sarge left behind at the convenience store robbery that were analyzed by S.H.I.E.L.D.'s newest recruit, Dr. Marcus Benson, the doppelganger is a 100% DNA match for the late Phil Coulson (minus possibly alien radiation markers and foreign methyl groups). Benson, who was brought into S.H.I.E.L.D. by May as her pick to restart the S.H.I.E.L.D. Academy, was originally operating under the theory that Sarge was a Life Model Decoy, but LMDs don't have DNA. Benson was also aware that Coulson had died and was resurrected already, yet May insists that the Coulson she (and we) knew is really dead.
However, Sarge himself is keeping secrets. Pax referenced that Sarge had a "past life" he's not going to tell anyone about, which hints at some possible link to Coulson. And yet, Benson discovered a biological hard drive in the neck of Tinker, a deceased member of Sarge's team, and the footage on the drive Benson and S.H.I.E.L.D. Director Mack Mackenzie watched showed Sarge and Jaco on another planet that was disintegrating into dust (visually not unlike how people fade to dust as a result of Thanos' snap with the Infinity Gauntlet).
In the footage, Sarge was carrying a huge, alien tech gun, which is identical to his weapon on Earth that he needed P-E-Gs to power. Sarge was about to fire his weapon before he was interrupted by May's fight with Jaco and Snowflake. The implication is clear: Sarge and his squad mean to destroy Earth for some unknown purpose.
Later, after May called Sarge "Coulson", Jaco asked what that word means and Sarge replied, "I don't know, but it rings a bell". It's possible Sarge is either lying or Sarge somehow is Phil Coulson reincarnated yet again, but he's unaware of his "past life" as the heroic Director of S.H.I.E.L.D. (perhaps because of some kind of swap of Sarge's mind with Coulson's body). Whatever is up with Sarge, the truth will surely be revealed as Marvel's Agents of S.H.I.E.L.D. season 6 continues.
Marvel's Agents of S.H.I.E.L.D. airs Fridays @ 8pm on ABC.