It's sad to think omegas in this omegaverse r only given rights after they're gotten pregnant and ur special if ur kid is an alpha at that. But to focus on the plus, I think it suits both their personalities well with the plot of the story and how it went on, how Levi is an alpha and Eren is an omega seems kinda believable to if u put it this way and how they're situation is so difficult and the one pulling them together is Eren, trying so hard...it's kinda believable really
Shingeki no Kyojin dj - Hangyaku Unmei