Iron Man may be incredibly dangerous in a fight, but the mutant Wolverine can take the billionaire Armored Avenger down with one deadly move.
Warning: contains spoilers for Iron Man #21!
Marvel's Iron Man is known for charging into battle with incredibly durable armor, but one single attack by Wolverine would end the Armored Avenger's crimefighting career in a second. Though the two superheroes fight on the same side, they have vastly different temperaments and powers, allowing for different possibilities while constructing fights. Iron Man #21 reveals that for all his massive wealth, Iron Man is simply no match for Logan - thanks to his armor's own incredible weakness.
Iron Man's name is a bit of a misnomer; his armor is constructed out of a gold-titanium alloy among other materials. The comics have even granted him self-assembling armor in the form of the Bleeding Edge suit and the Extremis armor. Iron Man has survived many blows while inside his suit that would easily kill any unarmored human (and while using Hulkbuster armor has survived combat with the Hulk, though he has rarely won any fights while using it).
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Unfortunately, Iron Man has never made armor out of adamantium - an extremely rare and durable metal that can withstand nearly any and all punishment, and in Iron Man #21, written by Christopher Cantwell with art by Angel Unzueta, Tony Stark is up against a villain armed with adamantium weapons. Chasing after an escaping hijacker, Stark is ambushed by adamantium micro-missiles and manages to evade all save one, which pierces straight through his shin armor, damaging his leg and severely hampering his flight control systems. Iron Man nearly falls out of the sky before resorting to emergency power.
Wolverine isn't just armed with enhanced senses and an impressive healing factor - his skeleton is also encased completely in adamantium. His claws are sheathed in the metal, allowing them to be razor-sharp and could certainly cut through Iron Man's armor. Wolverine wouldn't even need to stab Iron Man in the chest and through his arc reactor - all he would have to do is cut across Iron Man's shins, thus cutting off Tony Stark's ability to stand as well as his ability to fly (it is noted in the comic that Stark actually stores hydrogen in his boots, and critical damage would ignite the gas). Wolverine could most likely survive a hydrogen explosion, but Iron Man could not.
Wolverine has no armor but can survive more damage than a founding Avenger, an impressive feat. The two have worked together in the past, but Wolverine has little patience for egocentric billionaires. Iron Man's armor is quite strong, but Wolverine's claws can slice through it like butter - and all Logan has to do is go for the legs.
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