Adamantium Skeleton



In the Marvel universe, Adamantium is an extremely powerful metallic alloy that is virtually indestructible when rendered solid. It is for this reason that adamantium is injected as a liquid into the body, where its left to harden.

Several characters have undergone the treatment but for different reasons: Wolverine and Lady Deathstrike volunteered, X-23 (being a clone of Wolverine, was already embedded with adamantium from the start), and Bullseye (who suffered serious spinal injuries during a fall, hence why his spinal column was reinforced).

Side effects
As shown in X-Men Origins: Wolverine, a reinforced skeleton can pick up more vibrations and sound than a normal human body (as shown with Wolverine's increased hearing). In addition, the user weighs significantly more than before.

Limits
Adamantium, being a toxic substance, causes any user with a healing factor to continually use that power because it constantly tries to rid the body of it. As a result, healing factors are much weaker than before.

In addition, users become susceptible to magnetism. In an extreme case, Magneto at one point even separated the adamantium from Wolverine's skeleton; a gruelling process that caused his healing factor to burn itself out to prevent him from dying.