In William Congreve's "The Way of the World”, what is a reformed rake?

The character of the reformed rake is a Regency typical
portrait of the man who has learned to be street-wise, promiscuous, and now is willing
to be a good husband. The reformed rake is also the main part of the paradigm that
suggests that "bad men make the best husbands" assuming that women have a tendency to
look for the primal, instinctive, and dominating male. The paradigm also offers that the
reason behind this tendency is the woman's natural need to feel loved, wanted, and also
protected.

In The Way of the World,
the reformed rake is characterized by Fainall and Mirabell. They have scheming ways,
love to sneak around, and run around with whoever they please. Yet, they are the
archetypal men (at least Mirabell is) whom women would be most attracted to. 
Contrastingly, Witwould and Petulant would not qualify as "rakes" because they are too
into themselves to care about anyone else, and because half of the time their behavior
and tendencies renders them less than qualified to pose as "ladies'
men".