Now as a Fire Emblem fan as well as a fan of Atlus games, I absolutely loved the Wii U version of this game.  Even without any extras, I would buy this game day one for the Switch for that reason, but as we dive into what has been shown to us via the Nintendo Direct and Nintendo websites, we can see that there may be quite a massive encore to this game.  Now to recap the main parts of the game.  You play as a party of artists that try to advance their artistic careers either in music, T.V., etc; however, the world is full of enemies that try to rob people of their performa (energy created from artistic ability). You fight by using a Fire Emblem character as a source of power and you combine with that character to take on enemies. Note: None of the information is confirmed to be true, this is just my speculations based on what has been seen so far.

So most of the trailer we got showed us what we already know from the previous version, but about 45 seconds in we find out about a new song. Seen above from the Nintendo Direct we can tell it involved Kiria and Tsubasa.  Furthermore, since we know new songs usually originate from either story or side missions that involve the performers, and the fact that Kiria is in this new outfit in the cover, that this is likely some sort of mission-focused primarily on Kiria.

We then get the above image with no description at all.  I think this just further shows the mission needed to do to get the new song.  We see the main character followed by both Kiria and Tsubasa in what appears to be a new area.  Now, to be honest, I am only going by memory on this but this does not appear to be any location that was featured in the Wii U version of the game.

Then we get the above image which I feel is the hidden jewel of the entire video. First of all, if you look at the icon below it looks like the character that is attacking is Maiko, an NPC from the previous game that functioned as a manager for the artists/fighters in your party. Now it appears that she is a playable character but that’s not all the excitement from this.  The previous version of this game only featured Fire Emblem characters from Fire Emblem: Shadow Dragon and Fire Emblem: Awakening; however, it appears that this character is channeling the powers of a character from Fire Emblem: Fates.  Maiko’s current form resembles Azura which is seen from the blue jewel worn around her neck, the similarities of the hairstyle and color and the veil which appears to be based on the one worn by Azura in Fire Emblem Fates: Conquest.

Shortly after that, we get Barry Goodman another character that was previously an NPC that now appears to be playable.  Now without going into spoilers, there is a very important story-related reason why he was an NPC in the previous version; however, it appears this game had added new story elements that drastically evolve Barry’s character development which allows him to be playable. I also have a theory as to which Fire Emblem character he is paired with. If you go back to the image at the very top you can see what appears to be an appendage of someone that is hidden from sight near the back of the main character Itsuki.  Given that the armored character Kellam, an armored unit that is hidden inside the box art in Fire Emblem: Awakening in a similar matter, and the fact that Barry does have a connection with an armored Fire Emblem unit from Fire Emblem: Shadow Dragon (that’s about as close to the spoilers as I can get without revealing anything), it’s possible Barry is working with Kellam.

In the above image, the commentary very heavily implies that Tiki is a new playable character in the game and since she appears on the bottom of the screen just like Maiko and Barry it also reaffirms my previous theories on those two being playable.

From the Nintendo of Japan website, we get the above image which features a Fire Emblem: Three Houses outfit.  I also believe this image reaffirms my previous theory of Maiko using a Fire Emblem: Fates character since we now know for sure the new content references Fire Emblem games not mentioned in the Wii U version.