In this world there are people who use their power for good while others use it for ill intentions. The powerful rise and earn a title whether they are a hero or a villain and you yearn for that day, the day you'll earn your title as the greatest villain in the world but for now you are only a sidekick to the actual greatest villain in the world. Your master is Vion also known as the SHADOW BLADE, he is known for being good with every weapon he gets his hands on and his capabilities to fight in total darkness which is a skill you do not have.

Despite being Vion's sidekick you are nothing like him, you do not know how to fight and you are also too weak to do so but that doesn't make you completely useless, you have a talent when it comes to inventing dangerous weapons and deadly substances which is why Vion took you in the first place, without him you would still be in that orphanage forced to wear dresses with pink bows(you're worst nightmare). And then there's the greatest hero in the world, your master's sworn enemy, she's known as Cupid and she has the ability to fully take over a person's mind and body once shot by her arrow.

One day you were in your lab mixing a bunch of substances when you suddenly got the urge to try to gain your masters approval by capturing the hero by yourself and so you did. Luckily you actually managed to catch the hero... very surprising honestly.