Le Diable
Downfall.
Expelled from heaven, Satan and the other angels fell 'ruin upon ruin, rout on rout / Confusion worse confounded'.
Then the great blind poet John Milton set them up in hell in a palace called Pandemonium, an upside-down hierarchy of evil, a great and deadly theatre of hopeless pride where 'Satan exalted sat' in 'bad eminence'.
The Tarot of Le Diable - the Devil - implies unexpected failure. Satan expected his revolt in heaven to triumph.
If you invent a character based upon the attributes of this card - malevolence, subordination, malicious advice, violence, negative fatality - you will almost certainly give them pride too, enough pride to make them blind to danger, so that their fall will be unexpected, if not to the reader, at least to the character themselves.
Of course, at the same time, the Devil card implies a person liable to be tempted to evil, perhaps even to self-destruction. That would put a full stop in your story, but you may not agree. Evil, in your novel, may triumph over and over, raising and re-raising the stakes.
In this card, there is also a strong sense of bondage, often pictured in the chains with which the smaller devil are bound. It could imply addiction – to people or to things, to ways of behaving.
The Devil is a card of lust.
In contrast, Le Diable reversed is an image of release, or being freed, of throwing off shackles. Perhaps a mundane result could be divorce from an unhappy marriage, but it could also imply a more subtle development in your character. Perhaps he or she could emerge from self-deception to recognise the needs of another, reaching some kind of spiritual understanding, previously denied.
Rebirth.
