Jude Bellingham's coming of age, Marco Reus' return & the six reasons why Borussia Dortmund have become Europe's form team of 2023

The man leading Dortmund's charge this season is a certain English wonderkid, who became the youngest captain in Bundesliga history when Terzic gave him the armband in a clash with Cologne on October 1.

Handing such a huge responsibility to a 19-year-old would usually raise huge question marks, but Jude Bellingham is no ordinary teenager.

Having been signed from Birmingham City for the bargain price of £25 million ($30m) in July 2020, Bellingham now has two-and-a-half seasons of experience under his belt in the German top flight and Champions League. He also boasts 22 England caps, five of which were won at the 2022 World Cup in Qatar.

He's always been a huge asset to Dortmund, but he's reached a new level in 2023. Bellingham is no longer an unpolished diamond –he's the finished article.

Bellingham is making BVB tick with his performances in the middle of the park, providing invaluable support in the final third while also working tirelessly in defence. His footballing IQ is off the charts and his engine is second to none, which goes some way to explaining why every top club in Europe is poised to fight for his signature in the summer transfer window.

Dortmund have a chance in any game with Bellingham on the pitch, including at Stamford Bridge on Tuesday night. Inspiring BVB to the Champions League quarter-finals at Chelsea's expense would just be another standard day's work for a youngster that looks destined to become one of the great midfielders of his generation.

Marco Reus' Dortmund career has been full of ups and downs, with injuries preventing him from living up to the loftiest of expectations, but there is no doubting his quality when fully fit and firing.

Persistent ankle problems saw the 33-year-old sit out BVB's autumn schedule, which is why Bellingham deputised as captain, and it was feared that his career at Signal Iduna Park could begin to peter out.

But Reus isn't ready to take a step back from the big time just yet. The Germany international, who boasts over 100 goals and assists in Bundesliga competition, returned in January to complete Terzic's line-up and has shown flashes of his very best form.

His biggest contribution so far came in Dortmund's 4-1 win against Hertha Berlin, as he set up the opening goal for Karim Adeyemi before netting a stunning 25-yard free-kick. Reus also netted a penalty in their latest victory over RB Leipzig to move into second in the club's list of all-time top goalscorers, and Terzic is in no doubt about the forward's importance to his side.

“Marco is our captain, he plays an extremely important role for us," the BVB boss said in February. "We missed him a lot, so we’re just happy that he’s healthy again, that he’s fit again. The interaction with Marco has been good, he feels good. We know all about his qualities.”

Reus is even reportedly attracting the attention of Manchester United, and if he can avoid an injury relapse, his stock will surely continue to rise between now and May.

Terzic was brought back to the club last summer after the departure of Marco Rose, and the decision to appoint the former interim boss on a permanent contract has proven to be a masterstroke.

The 40-year-old was already popular among supporters for overseeing a DFB-Pokal triumph in 2020-21 and he has embraced the chance to really show off his coaching chops this season.

“As a coach, I like variability and flexibility – not just in tactical terms but also in terms of player profiles,” Terzic told The Athletic in January. “You need to be able to react to everything in a game."

The best illustration of that flexibility came in Dortmund's 2-1 win over RB Leipzig at Signal Iduna Park on Friday. Terzic saw his team crushed 3-0 in the reverse fixture, but small system tweaks reaped huge rewards on home soil.

Dortmund were happy to let Leipzig enjoy the lion share of possession, but by sitting back in a 4-1-4-1 formation, they were perfectly set up to exploit the visitor's weaknesses out wide on the counter.

Terzic allows the likes of Bellingham, Reus and Julian Brandt to roam freely, which helps them to combine to devastating effect between the lines. He also honed in on the importance of set-pieces over the winter, leading to a major improvement in output from dead-ball routines with six goals already scored in 2023 – three more than in the first half of the season.

Playing out from the back is usually a staple of this Dortmund side, with Gregor Kobel's impressive distribution skills from between the sticks crucial to that set-up, and they aim to keep their depth and width in order to storm into the final third as quickly as possible.

By favouring such a fluid system, Terzic has been able to bring the best out of BVB's most creative players without giving anything away at the back, and they are able to make adjustments depending on the opposition.

Terzicball is in full effect.

Julian Brandt's talent has always been undeniable but consistency had proven elusive for the German in his first three seasons at Dortmund following a switch from Bayer Leverkusen in 2019.

The 2022-23 campaign has been a different story, however, as the 26-year-old has smoothed over his rough edges to become one of the most reliable performers in Terzic's team.

Brandt has made huge strides forward physically and is now showing a drive to win that is rubbing off on his team-mates. He picked up the Bundesliga Player of the Month award in January, and has nine goals and five assists to his name from 31 appearances across all competitions in total this term.

The Dortmund star's future has been the subject of much speculation, with no sign of an extension being agreed as he heads into the final year of his contract and Arsenal reportedly among his suitors, but Sebastian Kehl has made the club's stance on the player clear.

“We are seeing Julian’s development every day. He’s taken a giant step forward – and we’re very happy about that," the Dortmund sporting director told Sport BILD last month. "I’m aware of the contract situation, of course, and we’re approaching the issue in a very positive and relaxed manner.”

Brandt is forming part of one of the most exciting attacking units in Europe alongside Adeyemi, Reus and Bellingham, and his continued presence will be vital to Dortmund's chances of landing silverware come the end of the season.

Dortmund reportedly saw off competition from the likes of Bayern and Liverpool to secure Adeyemi's signature last summer, with Red Bull Salzburg allowing a prized asset to depart in a €38m (£32.5m/$40m) deal.

Adeyemi scored 22 goals in his final season in Austria, but wasn't able to transfer that form straight over to Dortmund as he struggled to find his feet in his first few months at the club.

The 21-year-old drew a blank in his first 13 Bundesliga outings before finally breaking his duck in a 2-0 win at Bayer Leverkusen on January 29, which sparked him into life.

He scored again the following week against Freiburg, and also broke the Bundesliga's all-time speed record in the thumping 5-1 victory, which served as a tantalising preview for what was to be a breakout Champions League performance.

Adeyemi conjured up Dortmund's winning goal in their first clash with Chelsea, running from his own half and leaving the Blues' record-signing Enzo Fernandez for dead before rounding Kepa and tapping into the net to send the home crowd into raptures.

The Germany international was back on the scoresheet against Hertha Berlin a few days later, but he also picked up a muscle injury in that contest, and is expected to miss the second leg against Chelsea.

Adeyemi is Dortmund's wildcard – an explosive forward capable of providing match-winning moments – and they need him back on the pitch as soon as possible.

Before Adeyemi's arrival, Dortmund had signed another of Europe's most prolific strikers in the form of Sebastien Haller, who enjoyed an unexpected revival at Ajax after a frustrating spell at West Ham.

However, less than two weeks after his £27m ($32.5m) move to Signal Iduna Park from Johan Cruyff ArenA, the Ivory Coast forward was forced to pull out of training after feeling unwell.

Haller was subsequently diagnosed with testicular cancer, and so began a gruelling recovery process that included chemotherapy and two surgeries.

Remarkably, the 28-year-old was cleared to return to training in January, and he made his emotional debut for Dortmund from the bench in their 4-3 victory over Augsburg.

The former Ajax star then scored his first goal for the club in the win against Freiburg, which just so happened to fall on World Cancer Day. It was a huge relief for Haller, who had thought only of how best to repay the fans for their support during his time away from the pitch.

"I was thinking 'they have bought a player and after two weeks I can't play for I don't know how long,'" Haller said when discussing his battle with cancer in an interview with BBC Sport. "What a bad deal.

"Of course, I wanted to come back and give back the support they gave me. This was really important.

"They gave to me before I could give something to them. I was sick and they gave me support. But I always knew that I would make it."

Terzic, meanwhile, paid tribute to Haller after seeing him open his scoring account. "This goal came way too late," he said. "We had wished he had scored his first goal back in July and August when we signed him, but you all know the story since then. So, the goal came today, in front of the yellow wall (of Dortmund fans). It means so very much to him and so very much to us. We hope it was the first of many, many goals."

It's no coincidence that BVB's upturn in form has coincided with Haller's return to the fold. His story has been a source of inspiration for the whole squad, and it could well lift them to their most successful season in nigh on a decade.