Fire Emblem Awakening’s Avatar — the customisable player character Robin — has a Brand of the Exalt in one eye, which turns that eye golden. The game treats this as a visual customisation option at character creation and never explicitly explains its in-game significance until late in the story.
The Brand marks Robin as a vessel for Grima — the Fell Dragon whose resurrection is the game’s central threat. When the Brand is visible, Grima can perceive Robin through it. The fact that Robin’s Brand was available as a cosmetic choice at character creation means players who chose it were, within the game’s fiction, choosing to be more visible to the antagonist from the first moment.
Intelligence Systems built a character creation choice that retroactively became plot-significant. Players who chose the golden eye and then reached the story revelation had to reconsider their creation session in light of what the Brand meant.
The ending of Awakening allows Robin to survive Grima’s final destruction or sacrifice themselves to ensure it. The Brand disappears in the survival ending. The decision about the Brand was made at character creation; its resolution comes eighty hours later.
The detail work the devs put into areas most players never visit is what separates great games from good ones.
I’ve put 200 hours into this game and never caught this. The developers really reward the obsessive players.