It's A Wonderful Life 2007

Thunder (Ronald Cheng) is a god from the heavens who once helped Ding Dong, a mortal child, and who promised Ding Dong that he will always help him out whenever he's in trouble. When Thunder forgot all about his promises, he's forced to go to earth to help Ding Dong, now an adult and a total loser, solve all of his problems in life.