help i forgot the name of a bl where the bottom is a monster(?) and top is an agent/soldie...

help i forgot the name of a bl where the bottom is a monster(?) and top is an agent/soldier (?). The bot is the top's step brother (not related in blood). The bot always attracts monsters and goes into heat and his brother will step in help

I suddenly remembered it being ridiculous and was wondering what happened to the story now lmao