[Crossover] A World Known Only to Shadows

"I was born to serve my master." After the shadow's first master died and became a curse, he decided at once to find himself another master so he could survive. If humans have probationary periods, couldn't a shadow try out several masters? And so, a certain strongest one, a certain cult leader, a certain spirit medium king, a certain mackerel, and others... The pitch-black shadow knelt on one knee. Even when hated, betrayed, and used, he remained like a stubborn, naive child. "I am the shadow who depends on my master. Please, Master, give me a face, a name, and feelings, and finally, the right to keep living." Please, my master(s). After crossing the names of all his former masters off his little notebook one by one, the shadow, now with a face of his own, realized how hard it was to find a master. Just as he was about to give up, his first master's underling showed up and forcefully shoved a mouthful of spoiled chicken feet into him. The shadow couldn't fight back. The chicken feet took effect, and he saw his dead first master. "You belong to me." His dead master pinched his face and looked at the features he had spent a thousand years shaping for other people, then gave a terrifying smile. Confused shadow: "...No, I'm not a thing." [Reader Advisory] The shadow is absolutely swoon-worthy!!! This is a deeply angsty romance. #You ran after breaking hearts, so yes, you really are a piece of work# #Being the boss's shadow doesn't mean the boss is your love interest# #The most important thing about being a shadow is treating everyone equally# #The outside world is too dangerous, so I'll be my own master# Theme: Teaching you to grow.