Put simply, I generally do not factor New Game+ (NG+) into my analyses. Not because it lacks any informational value, but because that value is, for the most part, superfluous. NG+ is a means for players to replay the game with a familiar yet fresh experience, and any changes made to that end are almost entirely motivated by gameplay. For example, some of the more conservative changes are new corpses with stronger versions of existing items. These items are typically placed in areas which at least serve the meta-narrative of their location. A magic-resistant ring might be added to a magic archive, a ring belonging to a legendary hero might be plopped near a similar hero; these items usually convey such obvious and tertiary contexts while bearing no connection to their location otherwise, making their meaning to the narrative entirely inconsequential. The rings don’t add anything lacking from the base game experience. They are simply incentive to play NG+ and reward such players.
Among the more liberal changes is adding new enemy NPCs or encounters. In Dark Souls II, we can encounter two red phantoms in the Grave of Saints, a woman wearing the dingy set and a man wearing the Faraam set. The former are the pure white holy woman clothes dirtied by ash worn by the previous game’s primary Fire Keeper, Anastacia. The latter is featured as the protagonist’s armor in promotional material. This “Fire Keeper” wields a variety of lighting miracles with a basic chime hidden via an Illusory Ring of the Exalted, an item we can only acquire after beating the game without resting at a bonfire. Meanwhile, the “protagonist” is armed with the Ruler’s Sword and King’s Shield belonging to King Vendrick, once a would-be Lord of Cinder. And finally, he drops the Soul of a Great Hero while she drops a Ring of Soul Protection. Taken together, and their appearance there on NG+ is obviously a playful Easter egg for beating the game. It is only appropriate for a player who potentially became a Lord of Cinder and the Fire Keeper safeguarding his mission to be found amongst the graves of holy men, and that is probably all there is to their inclusion.
Once again, the meta-narrative and gameplay lie at the core to FromSoftware‘s decisions for NG+. In cases where this isn’t true, its canonicity is almost guaranteed to be incidental. Another notable addition in the same game is an early surprise attack by Freja, the spider coming in and out of a pit in Tseldora realistically leading back to its lair. Can this fit into the base game’s narrative? Yes. Does it matter? No. The same can be said for the souls of the Old Ones acquired upon defeating certain bosses on NG+. This added detail confirms outside implications that such souls have possessed these bosses, but whether or not we actually acquire them in the canonical narrative is still irrelevant. Even the NG+ utility to the Curved Nil Greatsword is a case of creative gameplay mechanics more so than serious lore implications. Overall, NG+ is a collection of fun what-ifs packaged as a revitalized experience whilst divorced from continuity, holding only minor evidentiary value in extremely select cases. It isn’t designed to keep narrative integrity, and so I don’t treat it like it does.