Help me find a bl

It was kinda sci fi? The bottom had tan skin and the top was this white lizard hybrid thing who had long white hair. The story (I don’t really remember it so I’ll explain as good as I can) was the bottom was living in this dome area because outside the dome was dangerous because of all the monsters. The bottom’s older brother was like a high ranking general or something. One day the top (the white lizard hybrid) broke into the dome and then something happened and the bottom ended up leaving the dome to chase the top. Then the bottom realizes that the monsters aren’t really monsters