Quote Originally Posted by Wadoka View Post
Here's the Great Question.

The Allags had the tech, and the power, to construct Dalamud and imprison Bahamut.

Why didn't they destroy Bahamut instead?

Narrative Causality? Plot Armor? It only makes sense, when you've captured bloody Megatron you break him down into his constituent molecules. You don't just wrap him in chains and dump him in the Challenger Deep.
They had the other primals imprisoned under Silvertear too. As far as the elemental primals go, they can't be killed forever. It's possible Bahamut has a similar situation and they were keeping him in a corporeal state so he couldn't be resummoned. It's also possible they were weaponizing him and had him up there as their ace-in-the-hole, given the armor/restraints he's wearing... The BCoB story touches on this too.