Anthony Paul Torre, 57, pleaded guilty to three counts of stealing and two counts of fraud after embezzling $1,030,000 from eight clients between 2010 and 2015.
The money was used to fund Torre's lifestyle and repay investors, the District Court in Perth was told on Monday during sentencing submissions.
Torres robbed his victims of opportunities and financial security, the court was told, with some suffering physical and mental health impacts.
His actions were motivated by "greed rather than need" and left his victims feeling betrayed, humiliated and embarrassed, prosecutor Jennifer Solliss said.
Sue and Gary Sheehan invested their superannuation with Torre after retiring from their careers as an aged care worker and a cabinet maker.
Torre lured them into investments worth hundreds of thousands of dollars before using a large swathe of the funds to pay his credit card bills.
Outside court, Mr Sheehan, 79, said Torre "totally groomed us".
Ms Sheehan, 77, said Torre was like their "new best friend ... for three years and then it went haywire".
"We didn't realise that we'd been ripped off," she said.
"He took us for idiots."
The couple said Torre's crimes left them destitute.
"We had no money," Ms Sheehan said.
"We had to think whenever we spent money. We were getting $63 a fortnight from Centrelink.
"It was very hard."
Ms Sheehan said they were forced to sell their assets off at a loss to survive.
"We were redrawing on our mortgage, looking at whether to sell a car, a caravan or the house," she said.
"We couldn't go to the dentist, couldn't get the eyes fixed, and even getting in the car was an ordeal, because you have to put fuel in the car."
Mr Sheehan said Torre was "a liar, a cheat, a thief, a forger and a financial advisor".
The couple said while much of the money Torre stole from them was recovered, they remained out of pocket by about $400,000.
Torre was originally accused of stealing about $1.88 million from his clients, but this was reduced to just over $1 million after a plea deal.
All but $289,000 was repaid by Torre or recovered from insurers.
Ms Sheehan alleged the eight victims involved in the case were the "tip of the iceberg" and many others were too embarrassed to come forward.
The matter had been listed for a five-week trial, but Torre pleaded guilty just before it was due to start.
He will be sentenced in the same court on Thursday.
