So, assuming this summary is true, let's take a look at the SD's amazing development:
> Is introduced as one of the two Gods of the verse and clearly one of the two main villains along with the Demon King.
> Doesn't appear anymore after chapter 224 and doesn't utter a single word through the entirety of the main series.
> Nobody seems to remember her at all. Not even Meliodas or Elizabeth. Almost as if she hardly existed in the main series.
> The author literally retcons the previously established fact that she was the one who cursed Elizabeth to further humiliate the Demon King and don't let her appear in the main story for whatever reason.
> Is fully introduced and "developed" at the later part of a movie beneath the average length despite the fact that she's one of the two main villains of the series.
> Her magic is a carbon copy of the Ruler, only that it's for physical attacks instead of magic.
> The rest of her abilities seem to be rather unimaginative and completely unrelated to the Graces (which also seems to contradict the way she was introduced initially;
showings signs of all the Graces in her, implying she could use all of those abilities). I mean, lightning was already being used by the Demon King and it does seem to be one of the very few abilities the SD uses in this movie.
> Is killed after probably 20 minutes of fight at best and without revealing any interesting info and lore.
> Her relationship with her daughter, the AA and the entirety of the Goddess Clan is left mostly unexplored.
We shat on the Demon King for non-stop jobbing and cliche personality and motivations, but my god does he still look far better than the Supreme Deity if all those summaries and the info we've seen so far are true. He pretty much got VIP treatment in comparison to his light counterpart lol.
Actually, if all of what I've written ends up being accurate like the info we've got so far seems to imply, the Supreme Deity might very well be one of the worst treated villains in all of the manga history. It's not that she was badly developed. The term "bad development" should be used for characters that actually got some sort of development IMO. As things stand now, I don't really think the SD was developed at all. Nakaba literally didn't even try at all when it came to her. If she was going to treat her like this, it would have been better to never introduce her in the first place and leave the DK as the only main villain.
Pretty much the same can be said for the entirety of the Goddess Clan btw. Dunno if Nakaba had originally planned to treat them all like this or some external circumstances forced him to do so. Leaving aside all of what this comment could imply regarding my opinion of Nakaba, surprisingly, I don't really think he's a bad writer. A good portion of this series shows this. The Mael/Estarossa reveal was executed brilliantly and there was a point in which the villains were developed and treated in a respectful way and things made sense. Sure thing, even those chapters weren't a complete masterpiece and had their own flaws (like any work of fiction really, it also depends on the perspective of each reader). But after a certain point, it just felt like he stopped caring (mainly after chapter 280 and beyond IMO).
Pretty sad I'll end up leaving this series thinking of what it could have been instead of what has been. I guess my last hope is in thinking the movie will be a little different from the summary, but this is quite unlikely (not to mention the number of concepts that should be treated demands way more than just 1 hour and 20 minutes in my eyes).