I remember the MC transmigrating into the body of the evil (Senior) Brother in a sect who always bullys the ML. At the start of the story the ML is young (maybe a teen?). He gets bullied by the senior brother (original bodys owner) and the other students. Because the original bodys's owner, who always gave the ML the wrong study material, ML now has very bad skills. The MC feels bad and gives him the right material but he knows ML can't catch up to the others so he helps him. MC goes to ML while he sleeps and infuses(?) his body with energy to help him. Thats why MC is always tired during the day and when MCs father, the sect leader, comes back and finds out what his son is doing he let's him sleep until noon and stops saying anything. If anyone remembers please tell me. I'd like to continue reading the Story but it's been too long to remember. Thanks a lot!