Cardiff - Shaun Edwards enjoyed 12 successful years as defence chief in Warren Gatland's reign as Wales coach, but will now be plotting a Welsh demise when he touches down in Cardiff with France this weekend.
Edwards departed the Wales set-up after Gatland returned to his native New Zealand, the Englishman picked up by a France now coached by Fabien Galthie keen to revive their fortunes.
So far, so good. Edwards' defensive mark was clear for all to see as France kicked off this season's Six Nations with a 24-17 victory over England, backed up by a 35-22 win over Italy that sent them top of the table.
"He's the most demanding coach I've had in defence," said France's South African-born lock Bernard le Roux, at 30 years of age the oldest player in a youthful Les Bleus squad.
"It's incredible what he does," Le Roux continued. "He's a perfectionist who works very hard. At 30, I didn't think there was much I could learn in defence, but with him I learn every day."
Edwards is a real players' coach, his no-nonsense approach demanding respect and industry.
Now 53, he's the most decorated rugby league player in history, with 37 winner's medals after starring at half-back for the outstanding Wigan team of the 1980/90s, as well as Great Britain.
With that background, it is fair to say he is no shrinking violet, as the French squad soon discovered.
"He tells us what we mustn't do," said flanker Francois Cros.
"He gets angry. From the start, he arrived as he is and he hasn't changed. He's never been shy.
"He transmits to us his convictions and his burning desire to progress, to win, and we've seen that in the first matches."
Edwards said he was looking forward to a return to Cardiff to take on Wales in round three of this season's Six Nations on Saturday, something he said was the tournament's "greatest test".
"I had a wonderful time in Wales and am looking forward so much to coming back.
"It's going to be a brilliant game with two good teams going hammer and tongs at it. Win or lose, rugby will be the winner!" Edwards told walesonline.co.uk.
"We have got a young side and are trying to mould it into a team for the future. Hopefully, we are doing a half decent job."
Edwards' time with Wales coincided with Gatland overseeing four Six Nations titles, something he would surely like to replicate with the French, notably as France are hosts of the next Rugby World Cup, in 2023.
"The time Shaun had with Wales was very successful," Wales centre Hadleigh Parkes said in his BBC column.
"He is well respected not only within Wales but around the world as well with the way the Welsh team has defended for a long period of time.
"You can already see his influence on the French. They have brought a lot more line speed and attacking the breakdown a lot more which is something he advocates."
Parkes was sure that Edwards would be able to fire up France for Saturday's game.
"One thing that Shaun is very good at is motivation," he said. "Shaun will ensure they are very hungry and will be getting them psyched up all week."
Edwards, who coaches and give presentations in French - "as all the lads in Wales will tell you I've never been much for talking when three or four words will do" - seemingly already has his ammunition.
"We were pretty good against England but probably took a bit of a backwards step against Italy," he said.
"If we aren't (good) for the full 80 minutes in Wales, we will get beaten."