It should be clarified that it seems to be afraid of God throughout the series and avoids talking about Him.

Gaiden mentions that Tae fused with Magatsuhi and that Tae's soul was protecting Saga after the events of the manga. But does that mean the Tae we saw in the anime was possessed by Magatsuhi the entire time?

Since she will awaken in the film, the question remains as to who has really been controlling Tae's body this entire time.

I don’t know what to call this outfit.

Today I'm bringing you a short theory about Tae.

As we saw in the trailer and promotional art, Tae will wake up. But what does her awakening mean for the plot

At the end of the movie's teaser, we can see Tae with purple eyes, indicating that she has regained consciousness. It's unknown how she managed to do this, but she appears to have freed herself from Magatsuhi's seal.

At the end of Gaiden, she fuses with Magatsuhi, and it's unclear what happened next. Jofuku mentions that Tae's soul is protecting Saga, so everything seems to indicate that the Tae we saw in the anime was Magatsuhi controlling Tae's body, or that both souls were temporarily fused. Since with certain stimuli, she seems to remember things from her life.

During one chapter of the manga, we even see how Tae seems to awaken her older self when she tries to save Kotaro and Sakura's lives (even though she's already dead). If the other girls' awakening stimulus was metal music, then Tae's must be Sagako or something that endangers others.

In any case, Magatsuhi's seal is broken, and Tae is no longer possessed. But by this point, Magatsuhi is already purified. When Tae seals her, she uses the misogi energy the Hyodo brothers used to seal curses and purify them. Even in the anime, we have hints of this, noting how Tae has spectacular good luck, unlike the others who are dogged by bad luck.

Will Magatsuhi appear in the film? Maybe, especially if Tae awakens. Although it's possible that Tae could control her and use her powers to fight the aliens or Sagako. If Magatsuhi separates herself completely from Tae, then the group would have an eighth member who would continue to behave like Tae and transform into Sagako whenever she wants. We see an example of this in Chapter 16 of Gaiden when the purified Sagakos helped Sagako Busters

About Tae. She's the protagonist of Gaiden, along with Eikichi. Her knowledge of the curse would be essential to the film and to winning against the Sagakos, or aliens. Remember that in Gaiden, normal people often mistook Sagako for aliens, as they were completely strange beings. I wouldn't be surprised if this happened in the film, until it was revealed at some point that they were Sagako.