OK, so you know how Hope and Lightning travel together in the first game?
As she journeys with Hope Estheim, she acts as his mentor and surrogate mother figure. Taking him under her wing, Lightning becomes more emotionally open
“Keep your eyes front. I’ll watch the rear”????
And Hope notable adds the Japanese honorific “sama” (in the Japanese version) to Lightning’s name. The title sama is usually used in addressing persons higher in rank than oneself.
At first, Hope starts off as naive, insecure, and sensitive. But then, in Final Fantasy XIII-2, after spending time with Lightning,
Hope has grown into an intelligent and confident leader, admired by many, but continues to show moments of vulnerability whenever he reflects on his past…
Hope may have gained some experience with Lightning. At least, that’s what the Final Fantasy Wikia suggests.
But the proof may come in Lightning Returns: Final Fantasy XIII. Lightning can enter a monster hunting tournament, only to shut it down later. She can also hunt monsters to extinction. And Hope’s close relationship with Lightning enables him to aid her in much of her predatory hunting.
And this is why I think Lightning is a monster hunter, as opposed to anything you were thinking…