Protagonist:

Name: Kanade Yoisaki.
Talent: Ultimate Composer.
Universe: Project Sekai.

Support:

Name: Sayaka Miki.
Talent: Ultimate Magical Girl.
Universe: Puella Magi Madoka Magica.

Antagonist:

Name: Marvelous.
Talent: Ultimate Space Pirate Captain.
Universe: Kaizoku Sentai Gokaigers.

Others:

Name: Carl Clover
Talent: Ultimate Vigilante.
Universe: BlazBlue.

Name: Ashlynn Ella.
Talent: Ultimate Animal Whisper.
Universe: Ever After High.

Name: Ren Amamiya.
Talent: Ultimate ???
Universe: Persona 5

Name: Roy.
Talent: Ultimate Marquees.
Universe: Fire Emblem Binding Blade.

Name: Yuga Ohdo.
Talent: Li'l Ultimate Invent.
Universe: Yu-Gi-Oh Sevens.

(Note: For the elementary school students, they are going to receive the Li'l Ultimate titles from Ultra Despair Girls)

Name: Maria Ushiromiya.
Talent: Li'l Ultimate Witchery.
Universe: Umineko naku koro ni (Umineko/Seagulls when they cry)

Name: Franziska von Karma.
Talent: Ultimate Prosecutor.
Universe: Ace Attorney.

Name: Vivia Twilight.
Talent: Ultimate Detective.
Universe: Master Detective Archives Rain Code.

Name: Ruby Rose.
Talent: Ultimate Huntress.
Universe: RWBY.

Name: Cloud Strife.
Talent: Ultimate SOLDIER.
Universe: Final Fantasy VII

Name: Flora
Talent: Ultimate Fairy of Nature.
Universe: Winx Club.

Name: Marinette Dupain-Cheng.
Talent: Ultimate Fashion Designer.
Universe: Miraculous Tales of Ladybug and Cat Noir.

Name: Kanade Otonokoji.
Talent: Ultimate Guitarist.
Universe: Super Danganronpa Another 2.

(Note: Kanade Yoisaki will refer to herself as her username, K.)

16 sinners. They soon shall be dammed.

Such beautiful people, but they will turn ugly in hell.

Who lives and who dies? Who will betray? Will they ever escape?

Just wait and see.