Abigail Williams is a villainous character in that she cold-bloodedly and deliberately sets out to destroy innocent people's lives. She knows full well what will happen to the people she falsely accuses of witchcraft and also knows that they're all completely innocent. Yet she goes right ahead and accuses them anyway, knowing that with each false accusation her power and prestige will only increase.
Andrea because she is the most focused. Tom is acting either immature which is not a good quality in a leader. Whilst Joe is not confident and is acting shy which is also not a good quality for a leader.