Mourners wept as the coffin -- his airforce colonel's cap placed on top -- left the cathedral for Maidan square, and was carried through the streets of the Ukrainian capital.

As the coffin passed, onlookers dropped to their knees.

Korenchuk, was referred to in the military as Beekeeper, and piloted a Soviet-era MiG-29 fighter jet in the 40th Tactical Aviation Brigade.

He was lauded as the country's "best pilot" in an airforce statement which this week confirmed the ace's death during combat.

Having flown from the very first day of Russia's invasion, Korenchuk had shot down a dozen targets, including a Russian bomber, the airforce added.

Among the mourners, many wore a badge on their arm showing a white skull on a black background, bearing the legend "Ghost of Kyiv."

- Birth of the legend -

In the opening days of the Russian invasion in February 2022, social media feverishly followed the exploits of the "Ghost of Kyiv", a fighter pilot who had reportedly downed six Russian warplanes.

A series of videos showed dogfights attributed to the same, as-yet anonymous ace.

One February 25 post showing an aircraft shooting down another and then performing a victory roll went viral -- but was quickly debunked by news media who sourced the footage to a video game.

That did not stop an official Ukrainian social media account from picking it up two days later.

"They call him the Ghost of Kyiv," the caption read.

"This Ukrainian airforce ace who rules the skies over our capital and our country has become a nightmare for Russia's invading planes."

Social media was flooded with speculation as to who this new Ukrainian icon could be.

For a time, the title was lent to Lieutenant Colonel Vyacheslav Yerko, of the same aviation brigade as Korenchuk.

Having gone down fighting on the first day of the war, Yerko was awarded the Hero of Ukraine medal, the country's highest honour, three months later.

It was then the turn of their squadron-mate, Major Stepan Tarabalka, to take up the fabled phantom's mantle.

But after Tarabalka's death on March 13, 2022, the army decided to quell the speculation and dispel the myth.

In truth, the Ukrainian ace of the skies had never existed.

- 'We are all Ghosts of Kyiv' -

"The Ghost of Kyiv is a legend created by Ukrainians," the army explained on April 30, 2022.

It said the figure was "a collective image of the pilots of the 40th tactical aviation brigade," with the army urging Ukrainians to "check the sources before disseminating information".

Yet for Andriy, among the mourners at Korenchuk's funeral, the ghost was flesh and blood.

"The 'Ghosts of Kyiv' were real, and they were Vyacheslav Yerko and Valentin," he said.

Like many, the serviceman in his 30s with a shaved head had been trained by Korenchuk, who he was close to.

Now the commander of an anti-missile battery, Andriy struggled to hold back the tears when talking about his friend.

"With their old MiGs, they shot down dozens of targets, which is rare, especially with these kinds of aircraft."

He smiled as he recalled how the legend took flight: "Russian propaganda kept saying that the Ukrainian airforce had been completely destroyed."

"So we thought, who keeps shooting them down? A ghost?"

For Andriy and his comrades, the myth of the ghost had become a "guardian spirit" for young pilots.

He pointed to the deathly image of the skull on his shoulder. "Wearing this patch is a point of pride," he said.

"Today, we are all ghosts of Kyiv."