Swallowing Sea

From NovelUpdates:

Jinhai City Public Security Bureau newcomer Wu Yu is meek and mild, a man of few words, and completely unconcerned about the trials and tribulations placed before him by his strict boss. All he wants is to simply get by at his job, be paid on time, and play the role of a background actor.

Nobody knew that this young man had a massive bounty placed on his head by a drug lord, as well as the youthful heroic spirit of a dragon-slayer from the abyss.