At that time, Stu had used his cloning ability to create an alibi for himself. He had been very successful at pretending to be innocent, but Luke had caught him with Sharp Nose.
In the end, Stu failed to kill his girlfriend, and he simply killed his partner, Billy. Luke stopped him just as he was about to kill Billy's girlfriend, but Stu used his cloning ability to slip away again.
The guy left a deep impression on Luke.
He was the only high school student Luke had ever encountered with such a savage nature and bizarre thinking, as well as such an unusual ability.
But the world was unpredictable.
This deranged and ruthless guy had escaped from Luke back then, but had been caught by the even more ruthless and inhumane Sentinel Services and turned into a test subject.
Luke didn't know if this was karma or just bad luck.
In the end, the "cloning technique" which Luke had hypothesized back then had still fallen into his hands.
