Mahmoud's quiet life as a construction worker ends when his DIY supercomputer intercepts a priority SHIELD alert labeling Steve Rogers a wanted fugitive. Before he can process the news, a STRIKE team ambushes his squat, throwing a fragmentation grenade through his steel door. Mahmoud slams the dial, transforming into the crystalline behemoth Diamondhead just as the blast hits. Shrapnel bounces off his skin as he wades into the soldiers, using crystal shields and launching spikes to incapacitate them without killing. To escape the pursuing helicopters, he builds a massive crystal ramp, sliding down and launching into the air before transforming into the jet-propelled Astrodactyl. He flies to Washington D.C. to find Rogers, but his attempt to buy parts at a Best Buy to build a radar jammer goes horribly wrong. He is cornered by a SHIELD agent and Crusher Creel, the Absorbing Man. Mahmoud shifts into Jury Rigg, frantically tearing apart printers and alarm clocks to assemble a makeshift light-gun that knocks Creel back. When Creel absorbs the metal shelving to become an invulnerable steel giant, Mahmoud swaps to the tiger-like Rath. Driven by Rath's aggressive, wrestling-obsessed mind, he trades brutal blows with Creel, ultimately defeating him with a devastating Polaris Piledriver that craters the store floor. He escapes the arriving Quinjets by using his newly built jammer to erase his radar signature, but the battle leaves him exhausted and desperate to make contact with the rogue Captain America before SHIELD's net closes permanently. His desperate flight through the skies of Washington is a race against time, as the electromagnetic noise of his makeshift jammer hums on his hip, keeping him invisible to radar but drawing the attention of local law enforcement who are already responding to the wreckage left behind at the electronics store.

Mahmoud catches up with Steve Rogers and Natasha Romanov at the abandoned Camp Lehigh, proving his alliance by using his custom jammer to deflect an incoming SHIELD missile. To find the secrets hidden within the run-down base, Mahmoud transforms into the blind, predatory Wildmutt. Using his heightened senses, he sniffs out the scent of old aviation fuel, leading the team through a hidden door to an elevator that drops them into a massive underground server room. There, they activate the ancient computers, conjuring the green digital face of Arnim Zola. The Swiss scientist proudly reveals that HYDRA has lived as a beautiful parasite inside SHIELD for seventy years, orchestrating global crises to force humanity to surrender its freedom. When Zola reveals that a SHIELD ballistic missile is thirty seconds from vaporizing the bunker to eliminate them, Mahmoud uses his hip-mounted jammer to force the weapon to veer off and explode harmlessly on the surface. With the clock ticking, Mahmoud transforms into Jury Rigg. Cackling with manic energy, he tears into Zola's monitors and server racks, ripping out wires, chips, and keyboards. He literally disassembles Zola's consciousness, downloading his predictive algorithm into a custom, X-shaped mass of wires and glass called the X-Device, effectively killing the digital Nazi. To escape the collapsing facility and the arriving Quinjets, Mahmoud shifts into Diamondhead, encasing the team in a blue-green crystal tepee and growing the gems at a diagonal angle to dig their way through the earth to safety. They escape, but they are now armed with a weaponized algorithm that can expose HYDRA globally if they can find a way to broadcast it. This stolen data is their only shield against the impending launch of Project Insight, which is scheduled to eliminate millions of potential threats in less than twenty hours.

At an abandoned dam, Mahmoud regroups with Nick Fury, Tony Stark, and Clint Barton. Working in the lab as Jury Rigg and Upgrade, Mahmoud helps Tony build a custom set of purple-and-silver Rescue armor for Pepper Potts, while preparing for the assault on the Triskelion. When the battle begins, the X-Device and Jarvis launch the Hercules app, instantly exposing every HYDRA agent worldwide on their smartphones. Mahmoud drops from a Quinjet, transforming into Diamondhead to shoot thousands of crystals into the helicarrier hanger doors, growing them into a massive mountain of blue-green spires that blocks the ships from launching. He tears through HYDRA forces as Fasttrack, Blitzwolfer, and Feedback, but the battle turns dark in the lower engine room. Caught in human form when his watch times out, Mahmoud is forced into a desperate, bloody struggle with a HYDRA engineer. As the man tries to drive a knife into his throat, Mahmoud shoots him in the leg, overpowers him, and drives the blade into the engineer's neck. The raw, wet reality of his first kill leaves Mahmoud hollow and shaking. He quickly forces himself to transform into Upgrade, flowing his nano-organic body over the helicarrier's controls. He merges with the massive ship, upgrading its weapons to laser emitters, stopping the captain's self-destruct sequence, and launching concussive green repulsor blasts to wipe out the HYDRA convoy on the bridge. The battle is won, and SHIELD is disbanded to form BRIDGE, but Mahmoud is left carrying the deep psychological trauma of taking a life while HYDRA's remnants regroup under a new, terrifying alliance. This lingering guilt will test his resolve as he realizes that the war is far from over, and that his enemies are already preparing a counterstrike that will hit closer to home than he ever anticipated.

The fragile peace of the newly formed BRIDGE is shattered when Baron von Strucker, Samuel Sterns, and Emil Blonsky launch a coordinated strike. They kidnap Sharon Carter, Antoine Triplett, and Jennifer Walters, the cousin of Bruce Banner. Realizing that the big-headed Leader intends to use Jennifer's DNA to engineer a stable, mind-controlled gamma weapon, Mahmoud knows he must prepare Bruce for the brutal war ahead. He flies Bruce to a desolate Colorado plateau in the Defiant, away from civilian eyes. Standing on the dusty stone, Mahmoud delivers the devastating news of Jennifer's capture, deliberately forcing Bruce to confront his deepest fear. The provocation works, and Bruce's skin turns a violent green, his clothes shred, and he transforms into the raw, destructive fury of the Hulk. As the green giant roars and launches a bone-shattering punch, Mahmoud activates the Omnitrix, selecting a massive, red-skinned form with four muscular arms and four eyes. He slams the dial, transforming into Four Arms for the first time. The shockwave of his transformation cracks the plateau as Mahmoud leaps to intercept the Hulk mid-air, wrapping his four massive arms around the beast's waist. They crash into the mountain side, triggering a rockslide as they trade earth-shaking blows. Mahmoud uses his superior height and multiple limbs to grapple with the Hulk, taking brutal punches to the jaw to test his own limits. This is not a fight to destroy, but a desperate, violent effort to help Bruce find teamwork with his alter ego, preparing them both to face the Abomination and rescue the hostages before Sterns completes his horrific experiments. The survival of the entire team depends on whether the Hulk can find his footing in this new alliance, or if his rage will consume them all.