Flashbang

They killed his father. Now, he'll do anything to get revenge.

Ten years ago, MC's father was killed by a ruthless member of an underground organization. Since then, he's lived a life feeling the heavy weight of revenge on his shoulders. To fulfill what he swore to do, he joins one of the organizations offering strength and allies to hunt down and eliminate the man who killed his father. MC stumbles into romance, new friends, and a path of learning the ways of the assassin. He may become strong enough to get his revenge, but at what cost?