The descendants demon slayer but different relationship

Mha x Naruto x kny

Black hair girl is itachi secret daughter sasuke doesn't know
Brown stain girl neji secret daughter not his family know
Red and green stain is todoroki x deku daughter
The three suck into the portal landed Tiasho era before tanjiro sell coal the 3 learn inflation and want find who person teleport into kny so they become demon slayer

Itachi daughter name-Emma
Neji daughter is-Elisa
Todoroki and deku daughter name-Emilia

Emma use water breathing(she learn it from Giyuu she is his student even they look similar personality also was adopted by urokodaki)

Elisa use flower breathing(she learn it from kanae she was her student become part butterfly sisters since she basically orphaned here Tiasho era)

Emilia use flame breathing(she learn it from Rengoku she is his second student besides Mitsuri mitsuri adopted Emilia become part of her family and her family approved )