A lot of those stories feel like they're chasing the same rush 'The Last of Us' got from Joel and Ellie, but with hedgehogs. They'll start with Shadow being this detached, mission-focused weapon who views Amy as a naive liability. The predictable turn is her relentless optimism becoming a corrosive force on his cynicism, like water on stone.
What I find more compelling, when it's done right, is when her light doesn't 'fix' his dark. Instead, it acts as a mirror. His world-weariness forces her to confront that not every problem can be solved with a smile and a hammer, making her kindness feel like a conscious, harder choice rather than a default setting. The tension isn't just 'will he soften?' but 'can her philosophy survive a reality he understands intimately?'
I dropped one recently where the writer had Amy slowly adopting some of his tactical, isolating behaviors to protect him, while Shadow, in turn, began performing small, pointless acts of gentleness—like leaving a single, perfect flower on her windowsill—as a silent language neither of them acknowledged. That silent trade of traits, without either character losing their core, is where the magic supposedly happens, though it's rare to find it executed without one of them becoming wildly out of character.