The woman — whose identity is protected by a publication ban — told CBC News the 17-year-old faked a bomb threat at her daughter's apartment, exposed their personal information online and trolled them repeatedly.
And he live streamed all of it to his followers.
"He is almost like on a stage with a live audience and he is performing to the hilt," the woman said from her home in Arizona.
"There was nothing shy about him. Nothing geeky. Nothing quiet. Nothing humble. Nothing subdued. He was so far the opposite that it was scary. This kid is a Jekyll and Hyde. He's a master manipulator."
No victim impact statement
The teen was sentenced last week to 16 months in a youth correctional facility after pleading guilty to 23 counts of harassment, extortion and mischief.
Because he spent eight months in custody awaiting sentencing, he only has another eight months to serve. A judge also sentenced him to an additional eight months under community supervision.
The Arizona mother and daughter were among more than two dozen victims from Florida to California. The teen also managed to shut down Disneyland's Space Mountain ride with a bomb threat.
The mother said she was surprised they weren't asked to give victim impact statements.
"I'm shocked that [my daughter] was not notified, because she absolutely would have been there if they so instructed or needed," she said.
"And she could have explained in detail the terror that she felt."
The woman's 22-year-old daughter is one of the female gamers the youth targeted for rejecting him online.
But by the time he threatened her, the teen was notorious for "doxing" and "swatting" victims — publishing their private details online and faking emergency calls that result in SWAT teams raiding homes.
The daughter knew what was coming and called police to warn them her apartment might be the subject of a hoax. Sure enough, the teen then faked a call to 911.
"Shortly thereafter, an entire SWAT team in full gear with rifles drawn show up at her apartment," the mother said.
"She opened the door, and thankfully they did not break it down."
'I felt helpless'
The next night it was the mother's turn. She said her phone rang around 10:30 and when she answered, the teen identified himself by his online handle.
"I just bolted up out of bed and I said, 'You are in big trouble,'" she said.
"We're talking international terrorism here, you live in Canada."
The mother said her daughter saw the whole thing happen on the teen's live stream and began recording it on her phone.
But what perplexed them was the way he appeared to trick internet providers out of his victims' home addresses by posing as an employee seeking information about customers.
"He would call over and over and over until he found an employee that would give him the physical location according to the IP address, without any verification that he was an employee," the woman said.
"One time, when he did this, somebody there gave out my daughter's information."
The woman said her daughter is planning a lawsuit against their internet provider in relation to the incident, which she said left them both traumatized.
"I felt helpless. I was furious and I felt helpless. I was afraid for her. I lost sleep over it, clearly, I was a wreck," she said.
"I honestly didn't know how long the emotional impact would last on her."
The woman said her daughter was key to the teen's ultimate prosecution: she filed police reports, gathered recordings of him attacking victims and spoke with investigators.
Psychological reports presented at trial noted the "sadistic delight" the teen took in carrying out his offences. He was also deemed a high risk to reoffend.
The woman feels the youth should have been tried as an adult. She said she feels his problems are deeply rooted.
"That's what's so scary about these people that do these awful things," she said.
"They're brilliant. So when you mix a brilliant mind with a sadistic brain, you've got a big problem."