After tying up a Melbourne woman and assaulting her, Jiangang Ji bound her children's hands, covered their eyes and stuffed them into the boot of their mum's car.
He drove away, sparking a citywide search for the five and three-year-old who were safely returned to their family after near 12-hour ordeal on August 23, 2021.
Ji's immediately regretted his actions and that should be a sign of significant remorse, his lawyer Carmela Pezzimenti told a pre-sentence hearing in Victoria's County Court on Wednesday.
But Judge Gabriele Cannon said if Ji regretted taking the children he should have returned them straight away.
Instead, after waiting for their father to leave for work and breaking into their house armed with a knife, he drove them to his Mitcham home where they were locked in a bedroom and, at one stage, left alone for four hours.
Their mother was able to untie her legs and run out the front door of their Blackburn North home to raise the alarm with passing drivers.
With her hand still bound she begged them to call her husband.
"He took my kids, he took my kids," she cried.
Ji, who arrived in Australia on a tourist visa in late 2017, had previously worked for the children's father as a plasterer in his building business.
A character reference in support of Ji indicated a number of employees had issues with the owner, including disputes over payment amounts and frequency.
Medical experts found Ji, now 38, had ruminated over the experience before eventually leaving for a new job, which improved his situation.
When he lost his new job because of coronavirus lockdowns, Ji returned to ruminating over his past employment.
Judge Cannon said it may well have been that he suffered difficulties with the father, but it had fuelled a vengeful plan that he executed on the man's family.
She suggested Ji was thinking in a disturbingly clear way that he might get away with his plan, because he knew he was dealing with people he might be able to shame into not reporting it.
"He knows that he's got these people potentially over a barrel because of the way he's conducted himself," she said.
Ms Pezzimenti said that idea was unrealistic at best, and while she wasn't suggesting Ji's reasoning for actin the way he did was good, it occurred in a perfect storm of conditions.
"He rationalised something that was clearly irrational," she said.
Ji pleaded guilty to aggravated burglary, false imprisonment, kidnapping and theft, and a jury found him guilty of assault and other charges.
There was no argument he faces a significant sentence, Ms Pezzimenti said.
Kidnapping alone carries a maximum penalty of 25 years.
Ji will be deported to China upon release, where he has a wife and two children.
His wife was pregnant when he left for Australia and he has never met his son.
Ms Pezzimenti said it weighs heavily on Ji that his children would be adults when he is released and returns to China.
Judge Cannon is expected to sentence Ji on December 13.
