Some changes from the WN for those interested:
Vernel jumps not because of Eterna but in the WN and novels Elrise had jumped down already to catch Eterna. Vernel's own narration declares as such as he had a very calculating and reasonable thought process about Eterna, Elrise jumping however... His body on the other hand immediately moved without thought the moment he saw Elrise go over the cliff.
About the wound, Elrise had a small internal panic about it, but on the surface she just looks curious and then she goes and picks up the wound and it moves away like a red thread. Elrise using her magic to instantly heal the wound and then using light magic to make a red thread appear. She explains to Vernel that a red thread must've gotten caught on her.