judging by how the Crow Mask acts, he looks like Desir from an alternate timeline or someone else from an alternate timeline who faced the similar hardships like Desir, but may have been wiped out way early coz the status divide dint bring them together to survive.....
I kinda just think that the author includes the guy just to have a "compare and contrast" session with MC, like how most authors would sometimes do. Then you will find all the unfair BS of being an MC, like how your friends don't drop like flies or somehow managing to know someone from the upper echelons and gain respect from them.