I'm so freaking lost with this manga. Seriously, what's even going on? What's even the whole idea of adding so, so many characters in a story about rangers and invaders? I can't even remember being so lost while reading a chapter since Fire Force.
Okay, so: We are currently, along with D, watching Shinya's memories of the Tokusatsu period of Dragon Keepers, which the current Dragon Keepers, is based on (facilitated by Magatia's dream world powers).
Hardly any new characters have been introduced this arc, or they're recurring from Sousei's Clone's arc where we saw flashes of his and Sanae's time on the show.
The entire point of this arc is to show us how we got to the current way Yellow is, and what to do about ending the destruction the Ranger's have wrought.
The Dragon Priestesses, who are Mikoto's (Shinya's Wife, and mother of his child) sisters, are used as the basis for the lore and power system of this story, and at some point are murdered and turned into Divine Tools, which the keepers use their powers for. All of this is tying together the many threads we have had set up throughout the story, and if you're confused, its because you missed or didn't pay attention to things earlier in the story.
This chapter, for example, reveals that the murder that destroyed the Toku show, done by Soushi Akabane (first mentioned in Chapter 100), was committed against the original actor for the Yellow Keeper (Tasogare, the blonde sleazy guy), and that Shinya Kiritani (the Yellow Keeper on the show and in the present) was the one who ended up handing him into the police, at least, indirectly (seemingly deliberately to end the show that was causing him so much grief).
The reason this chapter was so disjointed is because Shinya's mental state is falling to pieces as he struggles to juggle being a lead writer, an actor, and a father to an expecting child, and frankly, failing at two of those things. The constant flashing between him with dark shades on his face and bright shades shows these two sides (one positive, one negative) in contrast with each other as he struggles to sort himself out.
You have to use reading comprehension, and you have to pay attention to what's going on, otherwise you'll find yourself lost. You can't simply skim read a series with this much information and expect to understand it.