I Killed the Demon God in One Strike. Wasn’t That Just a Grass Monster?

Qin Feng transmigrates to another world, only to awaken what seems like the worst talent and most useless ability. One slash kills a grass monster. As the weakest monster in history, a grass monster can be killed with ease even by someone who hasn't awakened. “A top student, and this is the ability you awakened? What a loser!” “You think you can get together with the goddess? Know your place!” “I guarantee he'll never break through to the Demon-Slaying rank in his entire life!” Ignoring everyone's scorn, Qin Feng simply focuses on completing the tasks issued by the System. Human-rank monster? One slash. Demon-rank monster? One slash. General-rank monster? Still just one slash! One day, the supreme Demon God of another world awakens. The powerful tremble, and humanity despairs. Just as the Demon God prepares to slaughter every human, a young man raises his hand and swings his blade. As the powerful look on in shock, Qin Feng smiles and says, “That's another grass monster slain. Feels great... Hey, why are you all kneeling?”