Mercury has the highest resistance to combustion since it is always close to the Sun and never beyond 28 degrees from the Sun. Saturn has the least resistance to combustion, as it is the farthest away from the Sun in Vedic Astrology terms.
Anyway, aspects of Rahu to the combust planet nullify the combustion as Rahu sheds its darkness over the combustion. In such a case, neither will Rahu afflict the planet and nor will the combustion be hardcore.
In Oprah's chart, Venus is in deep combustion. As a result, she never really had a fruitful married life. In fact, that's the reason why she never tied the knot. Furthermore, the combustion is taking place in the 6th house, which further devastated her married life. Jupiter's aspect on the 4 planets in the 6th house and Rahu-Ketu's influence minimized the combustion by a lot.
Her highly favorable 4th house Mars, which is creating a Raj Yog, bought her, one-way ticket to fame. Mars is also in connection with Jupiter, which sealed her fate. Her 4th house Moon will also give good results since it is under the influence of Jupiter, and 4th house is the best placement for the Moon. These factors paved the way for her reality shows, and shows that talk about deeper things in life. Moon's influence there is also one of the reasons why she chose feminine topics. Mars in Scorpio sealed that as well....