In the Past Life: During the Titan times, Levi was a Captain of the Survey Corps and you were a scout. Levi had loved you when he first met you. During one of the missions, you and Levi were severely injured and bleeding profusely. You both interlocked your hands and made a promise to each other to find each other in the next life. You both died in Titan Forest. Future Life.: Levi wants to be with you through out his life and there aren't any Titans.