If you are refering to cain from the bible then the reason he killed 1/4 of the worlds population is because according to the bible, when cain killed his brother able there were only a total of 4 people on earth ( adam,eve, cain, and able) so one person WAS 1/4 of the whole population
Cain did not kill one quarter of the earth's population. In The Bible, Cain killed his brother Abel out of jealousy, but this incident did not involve a significant portion of the world's population as it occurred in the early stages of humanity.
Cain
The 1918 influenza pandemic, also known as the Spanish flu, is estimated to have killed around 50 million people worldwide, which was approximately a quarter of the global population at that time.
Abel was Cain's brother, that he killed.
I think you are referring to Cain. The story goes that Cain killed his brother out of jealously. When God found out he punished Cain by making any harm done onto Cain by others would come back on to them seven fold. This caused Cain to become a Vagabond and walk the earth until the Final Judgment.
Cain and Abel were Adam and Eve's sons. Cain killed Abel out of jealousy of his generosity.
When sin came to this earth, Adam and Eve had seen the green in earth withered, the animals turn against the humans and to see their son killed the other son.
He was killed by Cain.
Killed him
Because Claudius killed his brother {( Old Hamlet)} just as Cain killed his brother {(Abel)}
Cain and Abel were the sons of Adam and Eve. Cain killed his brother Abel out of jealousy and anger.
Yes they got separated when Cain killed Abel.
In the bible Cain , Abel's brother killed him. In the Norse myth beowolf the monster Grendel is supposed to bare the "mark of Cain"