ur pretty right except i wanna add a few key details, dan also made his friends gangrape the stepsister of the guy he is in 'love with' . eventually he even made the guy rape his own step sister. all of this cuz he wanted to see the face he made when he was suffering. though dan didn't 'directly' rape anyone (according to what i know), the impact was still the same as he was the mastermind of it all.
and basically hes on this killing spree because he wants to meet his victim (the guy hes in love with) in heaven
Yeah, I read the manga Trace, cause people calling Dan r@pist had me thinking no way... and what I saw was what you exactly explained. He didn't touch the girl. Yoshikazu (the guy he's bullying/first love) was forced by Dan and his friends to r@pe the sister, Hitomi. When Reiji (Mc at Trace) had a letter from Hitomi and did some DNA testing he found out a DNA of his brother step brother Yoshikazu and said that Hitomi his sister were pregnant with his older brother's baby. That was when a flash of Dan watching all this happened had me shockedddd....

the spoiler i got from trace readers are crazy some of yall are not prepared