Kriemhild
In the Nibelungenlied mythology, Kriemhild is one of four daughters of Ute. Her brothers were Gunter, Gernot and Giselher.Sigurd felt in love with Kriemhild, and helped Gunter to marry with Brunhilde in exchange of giving Kriemhild as his wife. Gunter accepted and both married with their beloved.
Lately Hagen killed Sigurd in agreement with Gunter. Sigurd was immortal after bathing on the blood of a dragon that killed. Only a little place of his back wasn't touched by the blood thanks to a leaf that posed here. Kriemhild was deceived by Hagen and talked him about that point, so Hagen was capable of kill him.
Then Kriemhild married Attila, king of the huns and avenged the death of Sigurd killing all his brothers and Hagen thank to Attila's army.