Ex-Wife? She's the Godfather.

Evelyn Song has been a quiet wife for seven years when her husband's mistress turns up pregnant and tells her to make room. Evelyn puts the woman in her place on the spot. Her husband is angry about it and takes the mistress's side. Evelyn makes one phone call to the military headquarters, and the elite unit he has been so proud of is disbanded. She ran the underworld of the city before the marriage and set that aside to help her husband rise. The organisation that backed him through those seven years was hers the whole time, and he did not know it. After the divorce she takes the Commander post he had been angling for, and the people he spent years courting take their orders from her. She also has a new lover by then.