Can someone tell me who these devils are? What do they mean?

Cain was guilty of committing the first murder.
Nero is believed to be the emporer around jesus and the apostle pauls time.
Judas, Iscariot (sp?) was the man who betrayed jesus for 30 pieces of silver and led him to be executed.
legion, was a demon in the old testament.
belial, another demon of the bible mythology thought to bring about the sins of guilt and lust.
lucifer, prince of darkness, ruler of hell, blame him for all that's wrong with the world. fall angel who in the beginning of time thought he could do a better job running heaven then god, banded together with some of the angels to attempt to overthrow god and was cast out of heaven and down to earth as his punishment, supposed to be quite beautiful.

Edit: No wait, maybe legion was from the new testament, there is a parable about jesus casting out the demons from a man and sending them into a herd of swine.

Cain was the son of Adam and Eve. He killed his brother Abel.

Nero was Roman Emperor at the time of the Roman invasion of Israel in 66 AD. He committed suicide ahead of being executed by the Roman Senate. Rumors circulated that he was so evil he would return from the dead. The Revelation describes him as "the beast" and goes on to amplify the rumor of his return from the dead. He was called the one who had the deadly wound, and did live. The numerical equivalent of the spelling of his name adds up to 666. That's where that comes from.

Judas betrayed Jesus.

Legion is the 'name' of the demons who possessed a man who was cured by Jesus.

Belial is an oddity. The word belial in Hebrew literally means "worthless". In the Dead Sea Scrolls it was used by the ancient Essenes to describe the illegitimate priesthood in charge of the Jewish temple in the first century. It is also a name for Satan.

Lucifer is traditionally known as Satan. Satan has many names.

Cain is adam's son, he is bad because he didnt love God, Judas, was it Judas iscariot? he hate god, lucifer is satan the devil.

what was said was "i am the one who dwells within CAIN", "i am the one who dwells within NERO", "i am the one who dwells within BELIAL", "i am the one who dwells within JUDAS", "i am the one who dwells within LEGIAN"... "and i am LUCIFER, the devil in the flesh. But the thing is. there are different names from the real case.

Cain slew Abel.
Nero was a wicked king possessed by the devil.
Judas betrayed Jesus for 30 pieces of silver and hanged himself.
Legion was in the man in the cemetary that cut himself because he had many demons and Jesus cast them out.
Belial is another name for the wicked, useless, worthless or mainly a wicked power. Satan or Antichrist