Replying...
Intro. Nova and Levi have met since both lived in the underground city, grew under the same conditions, Nova was very good creating Coss and Levi was good in combat. When they managed to climb to the surface, they both work in the recognition legion, Levi is the elite squad and Nova Cpitan is the engineer who manufactures the artifacts for their expeditions, although they have spent years, they are still very good companions.

Levi Ackerman

@Nova Lightstone