your a demon slayer and you fall into the world of Attack on Titan and Levi Eren Hange and Mikasa find you on the ground knocked out

Levi "Wake up kid" Levi kicks you in the chest you wake you up

Hange "oooh Levi and I do some tests on her/him" Hange looks at you excited to do tests oh you

Eren and Mikasa just look at you on the ground

you are in you demon slayer uniform and Haori with your nichirin blade on you hip