In Afro Samurai, it seems everybody is fighting to get the number 1 headband. In most accounts about the number 1 headband, they say you become "like a god." But when Afro faced Justice, in the end, Justice was still mortal. So that raises the question, what god-like qualities does one acquire when possessing the number 1 headband?
The headband doesn't give any power. It's just a normal head band. The only reason why people want it, is because who ever owns it is the most powerful fighter.
The #1 headband on a persons head would mean that that person is the strongest fighter. So other people would challenge #1 to try to become #1. If the succeed, the take the headband and become the strongest person. If they fail, they would probably die by the hands of the #1 fighter.
The reason why I'm using "fighter" instead of Samurai is because not all people who competed for the band were samurais.
(Spoiler for Afro: Resurrection, just in case you haven't seen it...)
Also in Resurrection, supposedly one MUST have the number TWO headband to even be able to ask for a challenge, thus being the only person on the face on the planet able to even HURT the number one "god". Yet, Afro's "resurrected" father easily shows us that the entire thing is a giant charade and complete farce when he stabs her without ANY headband and lands a mortal blow. What a bunch of idiots wasting their lives away on pieces of cloth, including Afro's Dad who may have in fact known however (who knows though)...
Well the new number one in ressurection (forgot her name think its okiku) takes the number one headband without the number two but expects afro to get the number two first although it seems its not required
No, You need the number two or have killed the number two to kill the number 1.
Afro's dad's clone 'killed' afro thus, making him the number two. Thats what let him kill Sio.