US Agent has his own name if thats who you're talking about. But I'd like to see Bucky use the name 'Winter Soldier' again. He's a good fighter, but doesn't excel at the inspiration and leadership that Steve epitomized, and his enthusiastic ruthlessness is in stark contrast to Steve's distaste for killing.

'Winter Soldier' originally referred to Bucky's enslavement by Soviets, however it has attained a new modern meaning.The term is used specifically for honorable soldiers who protest dishonor in war--its meant to contrast to an old poetic line chastising the weak patriotism of the "sunshine soldier and summer patriot", who are only brave and loyal as long as the military is popular and winning.