You know, when you get past the initial 'cool power' hook, these stories often revolve around the same internal tension: is the protagonist's fate actually changing, or are they just swapping one form of bondage for another? The character starts with a cheat, yeah, but that power becomes their entire cage. Every relationship is suspect because it might be built on their influence. Every victory feels hollow. I've seen it done well where the 'fate' that changes isn't about conquering a demon lord, but about the protagonist's own morality unraveling. They set out to avoid a tragic backstory, but end up creating a more subtle, self-inflicted tragedy where they're the most powerful and most lonely person in the room.
A lot of the narrative weight hinges on whether the author treats the power as a toy or a curse. If it's just a tool for wish-fulfillment—getting rich, building a harem, crushing enemies—then the 'fate change' is superficial. It's power fantasy. But the more interesting ones, like some arcs in 'The Beginning After the End' or even certain fanfic interpretations, show the character desperately trying not to use their power, because they know it corrupts everything. Their fate becomes a tightrope walk between using the power to survive and losing the very self they wanted to preserve. The external destiny of the world might shift, but their personal fate often circles back to isolation.
Ironically, the 'changed' fate can look a lot like the original one, just with nicer furniture. A character destined to be a tyrant might still become a tyrant, but a 'benevolent' one who mind-controls dissenters for 'the greater good.' The power doesn't free them; it just gives them a more palatable rationale. The real fate change, when it happens, comes from a voluntary limitation or rejection of the power, which most stories are too timid to explore fully. That moment of choice, not the power itself, is where character is forged.