My ideas for an Ayumi Tachibana challenger pack:
Fighter: Ayumi Tachibana
The default look is her Missing Heir 2021 outfit, with the school uniform getting two alts. Personally, I think the Missing Heir outfit looks great and feels more unique than a school uniform tbh. Both outfits get fighter spirits, though. Other colors could reference other characters, such as an orange dress as a nod to Azusa Ayashiro, or a rose-colored dress to reference Ms. Hayama.
Stage: Ushimitsu High School
A walkoff on the left and on the right a three-story school building. You can see some teachers in the building during the day, but after the sun sets you may see something else...
Featured music:
bold indicates a new arrangement, if not bold assume it's from the Switch
Famicom Detective Club Medley
Utsugi Detective Agency
Investigation
Ending (The Missing Heir)
Title (The Girl Who Stands Behind)
Scramble
Interviews
Police Station
Madness
Classic Mode route:
I was going to say characters that originated on the Famicom, but that may be too similar to Pac-Man's. Maybe something where you "investigate"seven other fighters and eliminate one each round until the final suspect (Bowser or Ganondorf) is left, and they're the boss of the route? Otherwise, a "Back to the 80's" route where only characters introduced in the 1980's are fought:
Round 1:
on 75m
Round 2:
on Duck Hunt
Round 3:
on Mushroom Kingdom
Round 4:
on Skyworld
Round 5:
Ayumi on Temple
Round 6:
on Suzaku Castle
BOSS: Dracula
Spirit Board:
I mostly made spirits for characters that you meet very early on and could have easy to make battles, to avoid spoilers. I saw the art book and I'm unsure if the 4-star spirit has actual artwork they could use that's isolated but who knows. I have ideas for some, some are incomplete lol
Protagonist (Famicom Detective Club)(***) (Famicom Detective Club Medley plays)
Shunsuke Utsugi (***) (Vs. Robin on Fourside, Utsugi Detective Agency plays)
Zenzou Tanabe (*) (Vs. Luigi on a foggy Luigi's Mansion, Investigation plays)
Amachi (**) (Fight on Tomodachi Life Omega, coffee food item spawns very frequently, Investigation plays)
Dr. Kumada (**) (Vs. Dr. Mario, Investigation plays)
Mr. Komada (**) (Vs. Mii Brawler on Ushimitsu High School, Vince AT spawns, Interviews plays)
Ms. Hayama (*) (Vs. Daisy on Ushimitsu High School, Timed stamina battle where the enemy avoids combat, Scramble plays)
The Girl Who Stands Behind (****) (Vs. Ayumi on Ushimitsu High School, The enemy is invisible and has a sudden FS, Madness plays)
That's all I've got for now, though