Not many people realized though that chasing Ultima Weapon around like that was basically a rehash of fighting Deathgaze in FFVI, who was fought in a similar manner (although you couldn’t see where he was sadly – he just randomly attacked you while flying in the airship at the end of the game). He even drops a powerful item once it’s defeated too (although a summon spell and not a weapon – the Bahamut magicite).
Also, you do know that once Ultima Weapon is destroyed, it allows ground access to the Ancient Frog Forest as well (which before required a mountain-climbing chocobo to access), although the weapons it contains are underpowered compared to what you’d probably have at that point in the game. Still an interesting little diversion none-the-less.