Long ago, in Ernesto's eleventh regression, he found love despite being torn by his multiple failures to save Ndulou.
Reshmin, an elf that he met in the middle of Ernesto's mission, made Ernesto fall head over heels for her. She was also his escape from the battlefield and a source of comfort in his despair.
Ernesto has so much faith in Reshmin that he doesn't mind telling her everything he's planning, including how he'll keep his brother Ndulou safe. However, Reshmin betrayed him, which caused Ndulou's death on his eleventh regression. He committed suicide at the time after killing Reshmin.
It's a bad ending for their love story, but Ernesto didn't expect to meet her again in this lifetime.
They were both adults when they met in Ernesto's eleventh regression, so she appeared younger to him, but he was certain that the elf in front of him was the one who had betrayed him.