A group of authors enter an infinite world. Every time they clear a level, they get a chance to summon the protagonist from one of their own books to help them clear the next one.
Author 1, sprinting: "Holy crap, didn't I set your IQ at 250?! Why is solving one clue so hard for you? And you even brought out the hidden boss?"
The protagonist runs ahead of Author 1: "You have the nerve to say that! Did you even write me according to my character profile? You wrote me as a complete idiot in the book! Where's my intelligence?!"
Author 3 summons their protagonist, only for the protagonist to attack them as soon as they appear.
Author 3 asks while dodging: "Why are you hitting me???"
Protagonist: "Because you killed off my wife! She didn't have to die, but you made her die just for the angst!"
Author 3: "I was wrong, boss, I was wrong!"
Author 9 summons their protagonist: a ghost.
Author 9: "Aaaaaaaaaah! A ghost! There's a ghost! Aaaaaaaaaah!"
The ghost grabs her by the collar: "If you're afraid of ghosts, why write about them?!"
Author 13 clings to their protagonist's leg: "I knew I was right about you! Of all the protagonists I've written, you're my favorite!"
The protagonist tugs at their pants: "Do you really like me, or do you like my ability to turn stone into gold?"
Author 13: "Come on, babe, talking about money ruins the romance. Of course I like you... Holy crap, give me that gold nugget!"
The protagonist puts the gold back in their pocket and walks away slowly. "Liar."
All kinds of authors and protagonists. Still deciding whether this will be a series of standalone arcs or focus on one pair. Work in progress.
Theme: As long as you're alive, that's enough