especially the way Zack's character arcs from this tough, protective guy to someone who melts into soft devotion. Early fics often stick to his canon persona—aggressive, fiercely loyal, but emotionally stunted. Over time, though, writers explore his vulnerability. There’s this recurring theme where he starts shielding someone (usually Daniel or Jay) out of duty, but the more he does it, the more his walls crack.
One of my favorite tropes is the 'slow burn' where Zack doesn’t even realize he’s falling until he’s in too deep. Like, he’ll throw punches to defend them, then panic when they get hurt, and suddenly he’s staying up all night just to make sure they’re safe. The best fics weave in his guilt—his past mistakes make him overcompensate, and that desperation turns into something tender. Physical protection morphs into emotional openness, like him learning to say 'I need you' instead of 'I’ll protect you.' It’s messy, raw, and so satisfying to read.