World One: "A Better Tomorrow," "The Longest Nite," "The Mission," "Young and Dangerous," "Infernal Affairs," "Fight Back to School," "God of Gamblers," "King of Comedy," "High Risk," "SPL: Sha Po Lang," "A World Without Thieves," "Police Story," "From Beijing with Love," "The God of Cookery," "Goodbye, Mr. Loser," "Yakuza"...
World Two: "Let the Bullets Fly," "The Master," "Ip Man," "Kung Fu Hustle," "Mr. Vampire," "Mr. Vampire II," "Mr. Vampire III," "Exorcist Master," "New Mr. Vampire," "The Musical Vampire," "The Taoism Grandmaster"...
This book draws on movies, TV dramas, games, and anime. Nothing is left out. It's a pure web novel that breaks the mold and delivers explosive thrills.
The protagonist isn't a cop from the start in the first world.
(Note: Most Hong Kong crossover stories seem to use a cop working undercover as their premise. Let's write one where the protagonist isn't a cop!)