WARNING: SPOILERS FOR THOSE WHO HAVE NOT WATCHED GEED
Alright, here we go (pun not intended).
Some people may have thought of this after viewing the first episode of Geed (if you have not, go here: https://youtu.be/c4BD3dstueY, or support them on Crunchyroll!). Here is my take on what the whole series of Geed might be about. The following may not be oh so spectacular, nor breath-taking, but please bear with me.
Ultraman Geed: Opening
The opening is most controversial. The first scene we see is King, using his powers to bring a broken planet back together. Some people may view it as purely aesthetical, but I believe there is something deeper to it.
There is a possible meaning to this: he did indeed fix what Belial had done and instigated, the Crisis Impact. The color of his energy, golden, is also a reference to what I will mention later on.
From there onwards, we see the titlecard (oh, Orb Origin's capsule), character introductions, the transformation, etc. What spikes my curiousity, and I'm sure some of you might've already noticed, is Early Belial appearing before the rise scene. We will get to that later.
Then we have the fight scenes, group shot, and done.
Orbs of Light
Apparently, the series also introduces some orbs of light, Little Stars, located within several individuals, an example being the girl from the episode. Notice their color; golden.
EDIT: From the second episode, the Little Stars appear to be the ethereal essence of the Ultra Capsules.
So basically, the timeline is this:
Belial... produces/creates Geed as a sleeper agent, who destroys Reibatos, who he deems useless, and sends Geed to eliminate.
He gains back the Giga Battlenizer, and through unknown means, causes the Crisis Impact. The Ultras are unsuccessful in stopping it. Belial disappears. In the midst of this event, Hikari creates the Ultra Capsules.
King appears too late, and he uses a large portion of his powers to restore that universe. His powers are scattered across the rebuilt Earth, initially the core of the Crisis Impact Blackhole, as golden orbs of light. He may have used the Ultra Capsules to assist him as well, in reference to episode 2.
Geed is sent to this Earth as a sleeper agent by Belial.
Early Belial awakens to these orbs of light, and separates from Rayblood Belial, leaving the latter weakened. Rayblood Belial creates the Kaiju Capsules, bootlegs of Hikari's, and sends his messenger Kay.
Early Belial builds the underground base and Rem, to guide his son when he matures.
Kay seeks to eliminate these orbs of light, and Riku unknowingly fights him, unaware of his status as a sleeper agent, as Geed.
So this is basically my theory for Geed, with some ideas from the discord. Spot any flaws, or like to add anything else? Comment below, let's all discuss.