Gerun Oracles

[Kaiser-Ace]

... that said, this is just a basic template. Details change, but there's not always going to be a killed / resurrected / imprisoned dragon. As for Nidhogg, I have a very hard time believing he'd ally with Garlemald; while his hatred is directed primarily at Ishgard, he seems to hold all mortals in contempt. It should also be noted that the "Nidhogg" we're fighting now isn't the genuine article, but a manifestation of his hatred that lingered in his eyes. The English version calls him simply a "shade," while I believe the Japanese version calls him a "demon dragon" (as opposed to his original designation as a celestial dragon).

Hmm, that would effectively make Nidhogg a Yokai/Akuma by japanese standards. But I think "Shade" would be a mislabeled. Shades have little to no influence over the material world so Nidhogg retaining the ability to kill would make him a Wraith. A very powerful and dangerous Vengeful Spirit

[Zohar_Lahar]

Hmm, that would effectively make Nidhogg a Yokai/Akuma by japanese standards. But I think "Shade" would be a mislabeled. Shades have little to no influence over the material world so Nidhogg retaining the ability to kill would make him a Wraith. A very powerful and dangerous Vengeful Spirit

Just like the Bahamut that came out of Dalamud.

[Kotemon]

Just like the Bahamut that came out of Dalamud.

Didn't Tiamat say that particular Bahamut they summoned was not the one that died during the Allagans invasion, but something entirely different (even she hoped it would be until she saw what was)? Just like how that other Dragon said that the Shiva summoned was not the original Shiva but something else created from her mind.