Responses
I think it's My Foster Child Became a Hero and When I Went to the Celebration I was Imprisoned, appears in ch 5 of this anthology https://www.mangago.me/read-manga/i_m_mediocre_but_i_m_loved_in_a_different_world_anthology_comics/
Does anyone know the name of a bl story where the uke has long black hair and is a mage that reincarnates to a story and finds the seme a villain as a child and raises him as a great warrior and believes the seme will be happy if he goes to war and become a hero and marry the princess. And when the seme come of age the uke kinda disappears so to find the uke, seme returns as a war hero and refuses to marry the princess which causes the princess ordering a collar that enslaves seme and since uke was so worried he reveals himself, which was just as the seme planned and he takes uke away