Quote Originally Posted by AuraAstra View Post
The concept of the Ultima Weapon as a boss has appeared in 9 of the "numbered" Final Fantasy games (as well as most of the spinoffs), with its first appearance in FFII. While the appearance is based on that of the Ultimate Weapon in FFVII, the idea is in no way unique to that game.
Not sure you can count that really. Soul of Rebirth was added for 20 year anniversary re-release for FF2 when it hit mobile platform in 2012 (I believe). So that was far from the first appearance of Ulitma Weapon in FF numbered franchise.

EDIT: But you're absolutely right in that Ultima Weapon is not unique to FF7. But I think the OP was making the point that the Ultima Weapon we see in FF14 was inspired by the FF7 version of Ultima Weapon.