Zero no Tsukaima: Futatsuki no Kishi

Synopsis

The supposedly dead Wales appears and takes Henrietta to Albion. He uses his vow from their earlier days to convince her into following him. The Musketeer Force chases Wales, but he repulses them with his magic. Saito and Louise go to rescue Henrietta by using the "Zero Fighter" with Kirche and Tabitha following them. Everyone then confronts Wales at Lagdorian Lake as he combines Henrietta's magic with his. Henrietta refuses to leave Wales' side. Wales, later revealed to be revived and controlled by Cromwell's Ring of Andavari, is defeated by Louise with a Dispel spell. Wales is released from the control of the ring and asks Henrietta to make a new vow that she will move on and fall in love with someone else, before dying again.

(Source: Wikipedia)