This idea won’t leave my mind so I’m just gonna write it out here.
So Kurapika’s life-draining skill which uses his Scarlet Eyes. is called Emperor Time.
I wondered why he named his skill that. Since he told his teacher he needed to have enough power to do things on his own, perhaps it was significance of his resolve. Maybe he wanted to be as powerful as an emperor. Maybe he wanted that sort of power. A power no one could oppose.
It’s a skill which would take away years of his life in exchange for him having the sort of unbeatable power a ruler or emperor would have.
And in the manga Kurapika is in the succession war by the Emperor of Kakin.
What if it’s foreshadowing?
What if a completely unpredictable thing happens and Kurapika takes down the Emperor of Kakin, and his lifespan ends and he dies?
Or, what if Kurapika takes down the Emperor of Kakin, and Prince Woble won the succession war but is too young to rule, so he acts as the Emperor of Kakin until he dies and Woble takes the throne? Hence Emperor Time.
....It would be literally Emperor Time, if Kurapika were to be Kakin’s Emperor until he died due to the effects of Emperor Time. His time as an Emperor would then end.
So I don’t know how or why but I think it would be an interesting idea.
For the ‘why’, I can think of a reason.
The Scarlet Eyes were one of the most beautiful colors in the world. One of the world’s greatest treasures. Hence they were coveted and exchanged in black markets.
So in a sense, even though the Spider carried out the deed, it was the world’s greed for materialistic things and expensive commodities that made the Scarlet Eyes coveted in the first place, such that there was a demand for the eyes, and the Phantom Troupe killed the Kurta and sold the eyes.
Queen Oito has mentioned when she was young she married the Emperor of Kakin for riches and gold so in a sense, Kakin’s Emperor Nausbi represents greed.
Kurapika himself has always been extremely righteous and he’s not afraid to dab his hands in dark things like the mafia to achieve his goals. He was also voted unanimously as leader by people who trusted him and his leadership abilities.
As he saw the last pairs of Scarlet Eyes by the 4th prince (not spelling his name lol) he thought to himself ‘Pairo, it seems my journey is about to come to an end. But where will I go? What is there left me to do?”
So he doesn’t have a goal after he collects all the Scarlet Eyes.
And what better goal than to make sure such a tragedy can never happen again?
It would bring meaning to the massacre of his clan. Why he survived the massacre, why he was the only one left.
To make sure no one else ever suffers the way he did again, by putting himself in a position of power.
Revenge is not for Kurapika, his teacher said he was chaining himself down and his friends disapproved of it, and he felt disgust at killing Uvo.
Hence he set out collecting the scarlet eyes, getting back the souls of his clan. At the same time, the effects of Emperor Time shorten his lifespan even on the ship, and he hasn’t found what he wants to do after he gets back the last of the eyes from the 4th prince.
Some people question why does the prince have so many of the scarlet eyes, did he know the Phantom Troupe, etc.
And I think since he chose getting back the eyes of his clan over revenge of the Phantom Troupe, he’s going to discover something about the massacre (since there are theories saying the Kuruta did something to Meteor City), something he wouldn’t have discovered if he had chosen revenge.
Maybe the 4th prince is linked somehow. Since he considers humans in crisis situations works of ‘art’ and the Kuruta massacre would certainly be ‘art’ to him.
Maybe the Kuruta did indeed do something bad in the past to be called ‘sons of the devil’ and be feared by people for their scarlet eyes, and Kurapika was just a kid and didn’t know.
Maybe there’s some secret behind Kakin royalty or Meteor City. Which led somehow to the Kuruta massacre.
Because Kurapika has always been fighting for the dead, living in the past. But if before his time runs out, he could fight for the living, he would truly have moved on to the future.
Whatever it is, I don’t think it’s coincidence Kurapika’s time seems to be running out, he’s in a succession war by the Emperor of Kakin protecting the innocent baby Woble, and his skill that takes away his life is called Emperor Time.