"The first one is always the best. The second one you're happy, but it is not like the first one."

La Rochelle wing Raymond Rhule started in the back-to-back final victories over Leinster, the first in Marseille in 2021, before helping his side come back from 17-0 down to win in Dublin last year.

Only Toulon, who reigned from 2013 to 2015, have lifted the trophy three times in a row.

Victory next year would put Ronan O'Gara's side in contention to be rated the greatest European side of all-time.

However, with a new format in play and Leinster in their pool, are the defending champions still the favourites? Or will there be someone else holding up the trophy at Tottenham Hotspur Stadium come May?

Format had 'a detrimental effect'

This year, the European Rugby Champions and Challenge Cup competitions return to a multi-pool format.

In response to the Covid-19 pandemic, each cup had been split into two leagues preceding the knockout stages, a move which received a mixed reception from supporters.

For this season 24 teams will be split into four pools of six, which still differs from the original format of four teams in each pool.

"We tinkered with the format during Covid-19 which had a detrimental effect on the engagement with broadcasters, supporters and players," chairman of the board of European Professional Club Rugby Dominic McKay told the BBC's Rugby Union Weekly.

"We would have loved to have gone back to the [previous] format, but that required nine weekends and because we only have eight weekends to play with we had to compromise a little bit.

"But it is [still] a massive step forward."

The top four from each of the four pools will qualify for the knockout stages, which begin with a last 16 in April.

Can Nienaber make it third time lucky for Leinster?

It seemed written in the stars that last year's showpiece, what was meant to be Johnny Sexton's final game for Leinster, the fly-half would avenge the 2022 final defeat by La Rochelle and sign off in style at the home of Irish rugby.

However, an injury in Ireland's Grand Slam-winning game over England ruled him out for the rest of the club season.

He watched as Leinster lost La Rochelle lifted the trophy for the second year in a row.

In 2021 Toulouse became the first side to win five European titles in total. Since 2018, Leinster have been hot favourites to add their own fifth star, but Leo Cullen's men have fallen at the final hurdle three times after impressing in the earlier rounds.

Double World Cup-winning coach Jacques Nienaber joined Leinster after guiding South Africa to three one-point knockout victories at this year's Rugby World Cup.

The knowledge of closing out the tight big games could be the final piece of the jigsaw.

Up first for Leinster is a trip to La Rochelle, who also knocked them out of the competition in 2021 at the semi-final stage.

"[We] have to go all in from the off and challenge ourselves regardless of who we are playing," newly appointed Leinster co-captain Garry Ringrose told Radio 5 Live's Rugby Union Weekly.

"There is always the responsibility that comes with the history and legacy behind Leinster and trying to do that proud. That is the challenge of it. It is not easy but that is what is motivating."

What about 'young and hungry' Saracens' chances?

Saracens are the other side who have beaten Leinster in a European final, with a 20-10 victory in 2019 at St James' Park.

That added a third title to the cabinet, but they were relegated in 2020 following persistent salary cap breaches, pausing their grip on European rugby.

Last season's Premiership champions, who were defeated by La Rochelle in the 2022-23 quarter-finals, will be quietly confident.

Captain Owen Farrell recently announced his decision to step away from next year's Six Nations to prioritise his mental wellbeing, meaning the Champions Cup is the biggest trophy on offer for the fly-half.

"Everything comes back to getting relegated for others but that is not the case for us," Farrell said.

"We have got an exciting, young and hungry squad that has the potential to be unbelievable. That is what our focus is on."

Toulouse without superstar Dupont?

France captain Antoine Dupont will not appear at next year's Six Nations after pursuing an opportunity to play sevens at his home Olympic Games in Paris.

Toulouse defeated La Rochelle in last season's Top 14 final, and are proven challengers. The signing of Scotland international Blair Kinghorn is likely to ease the blow of losing Dupont for large chunks of the season.

The scrum-half admitted "sacrifices" would have to be made in order to pursue his Olympic dream, which could well affect Toulouse's chances.

But a side littered with international quality will not doubt their ability with or without their star performer.

Ones to watch

Henry Arundell - Racing 92

The 21-year-old has been in flying form since joining Racing from London Irish, scoring four tries in his first three games.

Playing under former Leinster and England head coach Stuart Lancaster was a factor in luring the England wing to Paris, and his X-factor ability is already shining brightly.

Siya Kolisi - Racing 92

Leinster may have snared the double World Cup-winning coach, but Racing got the double World Cup-winning captain. The flanker joined the French club after becoming the first player since Richie McCaw to lift back-to-back Webb Ellis Cups.

Kolisi will look to use his leadership qualities to guide Racing to a first European title after two final losses in 2018 and 2020.

Damian Penaud - Bordeaux Begles

One of the stars of France's World Cup squad, Penaud scored six tries en route to a quarter-final exit at the hands of South Africa.

The 27-year-old recently joined Bordeaux Begles from Clermont Auvergne and has scored seven tries already.

Dan Sheehan - Leinster

The Ireland hooker was included in World Rugby's best XV of 2023 after a stellar year with both Ireland and Leinster.

Two tries in last year's final against La Rochelle were not enough to secure the trophy, but Sheehan will be key in Leinster's push for glory this season.

Jonathan Danty - La Rochelle

Another vital component of an impressive French team, the powerful centre has added layers to his game to become the complete midfield player.

A presence at the breakdown and a powerhouse in attack, his try in last year's final set his team's comeback in motion.

Key dates and pools

Round 1 - 8/9/10 December

Round 2 - 15/16/17 December

Round 3- 12/13/14 January

Round 4 - 19/20/21 January

Last 16 - 5/6/7 April

Quarter-finals - 12/13/14 April

Semi-finals - 3/4/5 May

Final - 25 May