Secret Invasion: Extremis, Cull Obsidian, and Super Skrulls Explained

Things get more complicated in the latest episode of Secret Invasion, which calls back to the past of the Marvel Cinematic Universe while pointing toward its future.

Emilia Clarke and Ben Mendelsohn in Secret Invasion
Photo: Marvel

This post contains spoilers for Secret Invasion, Episode Two.

Although she went about it in perhaps the worst way possible, MI6 agent Sonya Falsworth did uncover some crucial information in the latest episode of Secret Invasion. Not only are the Skrulls here on Earth, but they have a plan to get stronger.

More palatable is the way that G’iah discovers similar information, tailing a fellow Skrull to a secret lab. There, she overhears scientists talking about a Harvest, complete with DNA from various creatures. Some of those creatures we recognize, such as the beloved Guardian of the Galaxy Groot and the Frost Beast battled by Thor. But you might need a quick refresher about the other two notable examples, the remains of an Extremis soldier and the arm of Cull Obsidian. More importantly, the secret lab and the samples raise a question: What is the Skrulls’ real plan?


We first saw Extremis in Iron Man 3, as the invention of that movie’s true villain, Aldrich Killian. Killian and his organization Advanced Idea Mechanics (AIM) designed Extremis as a way to harness full human potential. Most immediately, Killian sold AIM as a way for wounded vets to regrow missing limbs. But Killian hid an important by-product of Extremis: the way it turned people into human bombs. Killian’s plans for Extremis necessitated a cover to blame it on, and thus borrowed the identity of Wenwu, father of Shang-Chi, to invent a terrorist called the Mandarin.

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Spurred by an explosion that nearly killed Happy Hogan, Tony started to investigate Extremis and learned that Killian’s right-hand man Coldblood had been using some of its explosive properties to wipe out those who got in the way by sending unstable soldiers to targets. Apparently, one of those soldiers fell into the hands of the Skrulls, who are analyzing their DNA in the secret lab.

Cull Obsidian

“Wong, you’re invited to my wedding,” shouts Tony Stark near the start of Avengers: Infinity War. What feat earned the future Sorcerer Supreme a seat at Tony’s nuptials (besides being the best character in the MCU)? His defeat of Cull Obsidian, the monstrous member of Thanos’ advance squad, the Black Order. Along with Ebony Maw (aka Squidward, according to Tony), Cull Obsidian attacked New York, forcing Tony and Wong — along with Spider-Man, Doctor Strange, but not the un-Hulking Bruce Banner — into action.

While Doctor Strange kept Ebony Maw from taking the Time Stone held in the Eye of Agamotto, the others tried to hold Cull Obsidian at bay. The battle ended only when Wong used his magic to portal Cull Obsidian away to a frozen wasteland, but not before the beast lunged out one more time. As the portal closed, it cut off Obsidian’s arm, where a disgusted Banner kicked it away.

Apparently, Banner kicked it over to the Skrulls, because G’iah sees the arm of Cull Obsidian in their secret lab.

The Super-Skrull

During his hostile takeover of the Skrull leadership, Gravik is asked the most important question of any would-be conqueror in the MCU: What about the Avengers? “Do you think I haven’t thought of that?” Gravik asks with a smile, which seems to be enough to settle the conversation. Nobody at the table wants to know what, exactly, Gravik thought up, but we viewers certainly do.

For comic book readers, the secret lab provides the answer to this nagging question. While Skrulls can change their shape to look like any other creature, they can’t replicate their abilities. So a Skrull may decide to look like the Sensational She-Hulk, for example, but it wouldn’t have Jen Walters’ strength or fourth-wall-breaking wit. In the comics, the Skrulls dealt with this problem through genetic experimentation, eventually changing a solider called Kl’rt into the Super-Skrull. In addition to his natural shape-changing powers, the Super-Skrull also possessed the powers of the Fantastic Four, allowing him to stretch his body, turn invisible, shoot flames, and clobber things at the appropriate time.

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The Fantastic Four won’t be making their MCU debut for a couple of years yet, so it’s clear that Gravik plans to make Super-Skrulls to deal with the Avengers. By splicing DNA, Gravik and his scientists will make an army that can grow tree limbs like Groot, shoot explosive heat like an Extremis soldier, control ice like a Frost Beast, and get its arm cut off like Cull Obsidian, probably.

But only time will tell if Gravik’s pseudo-Super Skrulls can counter the real threat to their plans in Secret Invasion: Nick Fury’s power to threaten someone through folksy anecdote.