And that's a side prepared for battle down to the finest detail.
Manly legend Steve Menzies played with and under the two-time premiership winning coach at the Sea Eagles and says there's no one in rugby league quite like Hasler.
"His work ethic, determination, his eye for detail, perfection, whatever you want to call it," Menzies told AAP.
"What he brought over from playing to being a coach was how to train [right] down to the last-minute detail on how he could get the best performance out of his body.
"He thinks a lot. He analyses a lot.
"But the reason why he's very successful is [that] he's evolved as a coach.
"He's always pushing, 'can I do this better?"'
Canterbury legend Terry Lamb's first observation of Hasler following his controversial switch from Brookvale to Belmore for the 2012 season was that the coach was always on the job.
"First here, last to go. That's his nature," said Lamb.
However, over time Hasler has become more known for his quirky behaviour than his on-field results.
Players talk about his intensity, and Hasler's appearances in front of the media are often pre-prepared theatrical routines, with nowhere to hide for young reporters.
"That's all true," says Lamb. "But there's a lot of humour in him as well. He loves his players. Loves having a joke with people.
"He's a very different person to what a lot of people out there know."
Canterbury's decision to poach Hasler from Manly was a no-brainer.
The logic of the signing was proven instantly by a grand final appearance in his first year, and has only been enhanced by this latest shot at NRL premiership glory.
However, it doesn't mean the Sea Eagles were the only club left shaken up by his controversial defection.
Canterbury's hunt for a coach of Hasler's stature also opened up some wounds at Belmore.
One casualty was Kevin Moore, who fell on his sword in July 2011 after being told he was unwanted.
At that stage, then Canterbury chief executive Todd Greenberg - now the NRL's second in command - was already on the search for a big fish.
Lamb remains close with Moore but admits the club had no choice but to pursue Hasler.
"Dessie is the ultimate professional and Greenberg went to poach him from the Manly people and I thought it was a great idea," he said.
The other man left shattered, initially at least, by Hasler's arrival was interim coach Jim Dymock, who thought he had his hands on the permanent job.
Dymock took over from Moore for the final rounds of 2011 with great success, but was told he'd only have the head coaching job for 2012, with Hasler to join the club the year after when his Manly deal expired.
However, Hasler's falling out with the Sea Eagles board escalated quickly and soon his deal at Manly was terminated, allowing him to join Canterbury immediately. That meant Dymock being bumped to assistant.
"You've got to understand [Dymock] was very upset at the time," said Lamb.
"He was upset but that's business, he understands that as well."
Menzies has heard both sides of the story when it comes to that most acrimonious departure and would rather stay out of the debate.
"I don't have a lot of contact with him, but I still get along with Dessie very well," he said.
The same can't be said for the Manly club, with relations bitter.
But like Menzies, they know exactly what to expect from Hasler's Bulldogs tonight.
"He revels in those big occasions," said Menzies.
"To bring the boys together for a common goal.
"Us against them."
- AAP
