Responses
It might be this one. But it one of the stories. Plot is MC is going to different worlds to tame the villain on the stories and the one you mention is one of them https://www.mangago.zone/read-manga/the_villain_loves_me_very_much/
Ok so it’s a Chinese bl and I only know remember a bit so it’s gonna be vague. The mc is a sort of like animal(?) or demon idk remember and basically he has something in him like a red orb or something that the ml needs. The ml and mc kind of end living together(?) as mc asked him to and if he did mc would give ml the orb(?) The ml wanted it for the person they liked(?) and in the end the mc end up giving him the orb after much reluctance and the ml left leaving the mc to die ig. The ml only came back after finding out that the orb was the mc’s life force(?) and knowing he would die. He then figured out that he loved the mc and deeply regretted his actions towards the mc. And that’s all I know.