Seven weeks into his disastrous campaign for glory in Ukraine, the Russian President Vladimir Putin knew he was in trouble.
He had dreamed of blitzkrieg, of shock and awe, of Russia's flag fluttering over the capital Kyiv by the weekend.
Instead his troops were outsmarted by a small but fierce Ukrainian resistance, and his generals were getting blown up on the battlefield.
Russia expected a war that would last no longer than two weeks, so fuel and food supplies quickly dwindled.
With one invasion, the world's most elusive strongman had pulled back the curtain on his own mystique.
He suddenly looked feeble, bumbling and needlessly cruel. But rather than admitting he had gone bust, Mr Putin decided to double down.
His war had already killed nearly 2,000 Ukrainians and displaced 4.6 million more.
But Mr Putin wanted more brutality and more bloodshed to snatch back the possibility of victory.
There was only one man for such a task.
And his ruthless tactics on the battlefield had earned him the nickname The Butcher of Syria.
Who is the 'Butcher of Syria' brought in to win Putin's war?
General Aleksandr Dvornikov is a career military officer who has been deployed by the Russian leader in key battlegrounds over the past two decades.
After graduating from one of Russia's elite Suvorov military schools, Dvornikov worked his way up the ranks to take command of a motor rifle division that stormed the Chechen capital of Grozny in 1999.
Grozny was battered by rocket artillery and cluster bombs, while ground forces seized control from rebel fighters in a siege that left thousands of civilians dead, and rendered it "the most destroyed city on Earth".
In the words of then newly installed President Putin, his troops had "fulfilled their task to the end".
But it was Russia's intervention in the Syrian civil war in 2015 where General Dvornikov gained his reputation as "the Butcher".
It's no secret that Mr Putin was horrified by the Arab Spring, which saw a wave of revolutions and armed rebellions against long-ruling authoritarian regimes across the Middle East in 2011.
Mr Putin was reportedly obsessed with gruesome footage of Libyan dictator Moammar Gaddafi's final moments.
The flamboyant and brutal ruler whose grip on power seemed assured was suddenly toppled by a Western-backed uprising and then murdered by his own people.
When an uprising sprung up in Syria, Vladimir Putin was determined to protect his ally President Bashar al-Assad — and perhaps stop the contagion spreading to his own doorstep.
First he offered only political support at the UN, as well as intelligence and aid.
But by 2015, Mr Putin had dispatched General Dvornikov as first commander of the Russian armed forces, to oversee a relentless campaign in support of the Syrian regime.
"Far from learning from others' mistakes, everyone just keeps repeating them," Mr Putin told the UN two days before ordering his military intervention.
"The export of revolutions, this time of so-called democratic ones, continues."
Under General Dvornikov's rule, Russian troops flattened several cities and obliterated civilian targets in the pursuit of military goals.
Russian forces were accused of war crimes including the deliberate bombing of civilians and aid workers in attacks on hospitals, schools and homes.
The general has been directly accused using tools of terrorism, torture, systematic rape and nerve agents.
A retired US Navy admiral even went so far as to describe him in an interview with NBC as "the worst of the worst".
He was widely criticised for his use of what are known as "dumb bombs" or "freefall bombs" — unguided, old-fashioned weapons that are far more likely to land on unintended targets.
While his tactics in Syria earned him the Butcher moniker, experts say General Dvornikov's brutality was within the bounds of acceptable behaviour in Vladimir Putin's army.
"All the Russians out there, they were extremely brutal and quite unconstrained about using firepower against cities and civilians," said Mark Cancian, a senior adviser at the Centre for Strategic and International Studies in the US.
"I don't think he was unusual in that regard. I think that's just the way the Russians fight."
Still, Mr Cancian said, the Butcher captured the attention and admiration of his boss.
"He was the first one there and that might have gotten more attention because he set the tone and it was the first time outsiders have seen the Russians fight a military campaign," he said.
Mr Putin bestowed the general with a gold star medal for his services in Syria, naming him a Hero of the Russian Federation.
After his perceived triumph in Syria, General Dvornikov was put in charge of Russia's southern military district.
Within his dominion was the Crimean peninsula — territory that belonged to Ukraine until Mr Putin annexed it in 2014.
And eight years later, when the Russian leader tried, but failed, to extend his grip on Ukrainian land, General Dvornikov was dispatched to fix his mess.
In Ukraine, Putin and the Butcher underestimated the enemy
Military analysts have drawn numerous parallels between the tactics Russia deployed in the Syrian civil war and those at play in Ukraine — even before General Dvornikov was in charge.
"What you're seeing in Mariupol is what you saw in Aleppo. Excessive use of firepower, and a disregard for civilians," Mr Cancian said.
Others have noted the targeting of civilian infrastructure, widespread use of disinformation and creation of humanitarian corridors that ultimately fail to provide safe passage are straight from the Syrian playbook.
Anastasia Kapetas, national security editor for the Australian Strategic Policy Institute, said while these tactics ultimately paid off for Russia in Syria, things aren't going the same way in Ukraine.
"Russia broke the rules of war in Syria, absolutely targeting civilians and non-combatants. This is illegal for good reason," she said.
"And they just did exactly the same in Ukraine because they got away with it in Syria, or they feel that they got away with it. And not only that, they were sort of lauded for their effectiveness in Syria."
She said while there were similarities in terms of the highly urbanised settings of these conflicts, Russia failed to account for one key thing in Ukraine.
"For a lot of these urban groups [in Syria], they had no way of fighting back. Ukraine is totally different," Ms Kapetas said.
"It has an army, a well-organised one that had been trained, who had been involved in operations in the Donbas for the last eight years. There've been various levels of national mobilisation. This is a much more prepared scenario than, you know, civilians in Aleppo."
The Islamic State militants who attempted to overtake Syria proved no match for Russia's military might.
But they were mostly armed with black market weapons, they were dependent on murky foreign donations and looted archaeological treasures for cash, and were soon gripped by defections and in-fighting.
Ukraine, by contrast, was fiercely motivated and united in defending its own territory from armed invaders.
And crucially, they had powerful friends in the West who were more than willing to funnel them intelligence and weaponry to stand up to the Russian Goliath.
'If you live by disinformation, often you die by disinformation'
In the years since Russia triumphed in Syria and faltered in Ukraine, there has also been a radical change inside the Kremlin.
Mr Putin has become increasingly isolated, surrounding himself only with those who agree with him, according to experts.
As a result, the information war played out very differently in Ukraine compared to Syria.
General Dvornikov has previously written about how crucial this was to Russia's strategy in Syria, arguing "without information operations, we would not have been successful in Aleppo, Deir ez-Zor and Ghouta".
While Russia used disinformation in Syria to discredit humanitarian efforts on the ground and obscure the use of chemical warfare, it has so far failed in Ukraine.
"[There are] too many eyes on this conflict for that kind of disinformation to have a huge effect on the ground to make a difference [for] Russian forces," Ms Kapetas said.
On the global scale, Russia's tried and tested propaganda machine has proved no match for Ukraine's more modern approach.
Instead, conflicting information about what's happening on the battlefield is being fed back up the chain, muddying the state of play and making it difficult for those in charge to anticipate the next best move.
It's this fundamental difference that some say could prove fatal for Mr Putin in Ukraine.
"If you live by disinformation, often you die by disinformation. It's very difficult for a political system that uses disinformation as a power projection tool … to not get caught up in it themselves," Ms Kapetas said.
The Russian leader has already begun a purge of his secret intelligence agency the FSB, with reports suggesting Mr Putin believes he has been misled about how the Russian military is performing in Ukraine.
This week's Victory Day parade was anticipated by many onlookers as an opportunity for the Russian leader to shift the focus of his war in Ukraine or redefine success.
But instead of any grand declaration or mobilisation of troops, there was a familiar refrain about enemies in the West without any major triumph to proclaim.
"It's been a month since Dvornikov has got in, has Russia made progress? No," Ms Kapetas surmised.
"They've had to retreat from key positions. They haven't managed to secure a land bridge to Crimea … Their naval assets in the Black Sea have taken hits. So there has been no real good news for Putin to take to the Russian people."
The offensive in Donbas may be Russia's last chance to draw some sort of victory out of Vladimir Putin's "special operation" in Ukraine.
