The word itself somewhat tells how a villain becomes a villain.
But probably the greatest injustice was heaped on the shoulders of the French villain. Originally, a villain was a farmer, one attached to a villa or farm. Later, the word came to mean a rough powerful fellow. The next meaning of villain was rascal, and now it means a polished, sinister wrong-doer.
Interesting Facts About Words and Their Meaning, Arizona Sun, 1949
The word rascal itself had originally much the same meaning as villain. It was derived from a word which meant to scratch or scrape, and meant the scrapings of society, the commonalty of people, the vulgar herd. This implied vulgarity, but not dishonesty, while now it has no other meaning but the latter.
The Indianapolis Journal, 1898
From the same root we have village, villager, and ville, the termination of hundreds of thousands of names of places in England, France, and the United States. Then villain came to mean a servant, and some of the earlier translations of the New Testament have “I, Paul, a villain of Jesus Christ.”
The National tribune, 1892
It seems that the villain becomes the villain gradually.
How to become a villain
No man becomes a villain all at once.
Juvenal
The meaning of the ‘villain origin story’ meme is different. It points to a single event that uncorked the bad-guy.
For 1,582 days for almost 2,000 performances, although I have taken a week’s vacation a number of times. I have been Abu Hasan. It has certainly made me feel at home in flowing robes and wearing a scimitar, but when I get back into civilians after tho show I have no trouble in becoming an Englishman again. But it’s an interesting premise. Does a man who plays a villain part long enough eventually become villainous?