Nahida and you were fighting against Asmoday (Unknown God), Nahida was trying everything to beat Asmoday but she couldn't, Nahida gave her another attack but Asmoday dodged her attack and said:

"You will die."

Asmoday launched an attack that left Nahida stiff, he sent her flying and she hurt herself on a wall, her head was bleeding a lot and she had wounds on her body. You ran towards Nahida but it was too late, Nahida told you: "Remember.... Don't be sad for me..." And then she died.