"I am already an enemy of the world, what's the difference?" Sven asked while shaking his head. He would of course want to become a dark creature if it means he'll become stronger!
Sven doesn't regret helping Caizher. If not for the man, he might not be alive until now. Sometimes, the best teacher is not those who taught you things when you already show huge talents. There are times when the teachers that taught you the most basic of things are the best!
All the complex things would all rely on the most basic ones. It was just like math. No matter how complicated the formula is, it would still rely on the four basic operations of addition, subtraction, multiplication, and division. Without knowing how to do these four, how can a person solve complex math problems?
Sven survives until he becomes this strong was because of Caizher! If he continues being with his former group, there is a high chance that they would be wiped out