Still don't think the Heart of Sabik needed explanation, nor do I really feel like Pandaemonium benefited from its inclusion.
I'd be curious to get a bit of a 'behind the scenes' look at the planning for Pandaemonium, because honestly it feels like it was stapled on in a later draft, either because the Anabeisos story needed some bulking up or for 'now let's finally Answer The Questions' fanservice. It doesn't necessarily feel like Pandaemonium needed it for the story, and it also felt like it came out of nowhere in that story.
...and I bet there's still some people, somewhere, asking 'but what is Sabik' as if the Heart of Sabik was a literal name and it's part of a big creature.