We had a kind of time loop in Rick Remender's Captain America with the appearance of a Worthy Thor and an Aged Cap together.
Well, could this be another? From Captain America #17… we had the death of Nuke.
And while those agents may not be coming back, in Death Of Wolverine, Nuke has. Somehow. Unexplained…
Doing what Nuke does best….
But rather than a patriotic villain, he seems reduced to a mercenary for hire by Hydra.
Folk come back from the dead all the time in comics, or course, ut usually there's a cursory line of explanation….