What is the significance of Bucky Barnes' metallic arm in his character arc?

Bucky's metallic arm is a pivotal symbol of his past as the Winter Soldier and a constant reminder of the trauma he endured. It represents his forced transformation into a weapon and the loss of his humanity. However, it also symbolizes his resilience and determination to overcome his past. It’s a visual embodiment of his struggle for redemption and a constant source of conflict and internal struggle.