I want to know more about this skin but the lore is non existent

Cause skins tend to not have any lore behind them, some exceptions like Queen Ashe and Pulse fire Ezreal.

In this case i believe all legendaries should have some lore.
even Trydamere got a video.

In eternum nocturne's case you have limitless possibilities.

he is a eternal nightmare who upgrades tech depending on timelines? is he a nightmare who takes the shape of whoever he most hates? endless choices

It's like the reveal post said: he's a re-imaging of Nocturne as a creature of the future that is attached to the timelines/future nigthmares instead of merely the dreamworld. So imagine as if Nocturne was exposed to the heart of the Tardis.

To directly quote:

<urge to bad fan fiction feel free to toss apples and other rotten fruit.

Phineas Bodewell was a back up summoner for any city state whose primary summoner is currently unwell at the time of the conflict resolution.
He was often mocked not only for this but his stark refusal to summon human champions.

Phineas hated violence and was forced by his upbringing into the role he now occupies.
However, In the constant conflicts and frequent mental strain even Phineas had a hefty workload.
His Chosen champion was Blitzcrank, Phineas had became a expert in ignoring the violent acts Blitzcrank caused and was caused to him. He wrote it off mentally as simply a big toy having fun.

It was another small blown up conflict by Demancian held towns versus Noxus Outposts and the Main Noxus Summoner had recently lost 3 fingers in a duel <not a uncommon occurrence in noxian>

Phineas was called up and felt this time, he would branch out and summon someone else.

Phineas poured over the summoning incantations of various Champions and concluded that he would once again not summon a human champion but a champion nonetheless that would silence his critics.

He choose Nocturne, in Bodewell's mind, he was just a big wraith, a creature he has seen killed dozens of time with little fanfare.
After Preparing a summoning circle he readied himself to the event and began the ritual as the announcer begin the countdown to the conflict.

"Welcome to summoner's rift" blared through the speaks as Phineas completed the summoning. Something was amiss, the stoic "wraith" Phineas expected to see was different, Red Steaks of electricity cracked around as the figure appeared.

This was nothing like Bodewell had expected, where the mist like figure was suppose to be stood a creature of black mirror like metal and pulsing red veins. The Blades on each arm seemed both terrible and alluring in their form. The face was not a misty stare but the cold metal face of death itself.

Phineas was terrified as he heard throughout the summoning chamber..."are you my nightmare or am i yours?!"


<like me to continue?>

Yes! Please finish the story

Honestly Eternum Nocturne's quotes remind me a ton of Brand.

Phineas deftly magically controlled Nocturne best he could but exerting exact control was hard due to his shaking figure and throbbing headache.

Everything normally that had become routine to the young summoner suddenly had a hidden horror. The wolves whimpered as the ebony tinted metal slashed through their frames, wraiths screamed and Golems seemed to bleed.

Killing champions was even worst, the blood colored figure laughed inside phineas's head as he delightfully eviscerated Fiddlesticks.. Phineas had no idea Scarecrows could beg for their life.

Second clear of the now screaming and shaking wraiths was interrupted by a beast of blue fur and teeth jumping Nocturne. Phineas took a sigh of relief, thinking that in death his champion would give him a moments peace. This was not to be so as The blood soaked metal figure torn into the now whimpering werewolf and Phineas saw true fear in Warwick for the first time in League history.

As the Match progressed, the carnage became a literal show of horrors..champion after champion dying with looks of shock and fear on their face. Phineas could no longer hear the cries of his enemies or the shouts of his allies. Only the Laughter ...The ever Eternal LAUGHTER

<part 3 if allowed>