A thing to remember here is that these posts are strictly meant for the particular planet position. Like, today we are looking at Ketu in Libra, so the description given here may change for you if your Ketu is although in the sign of Libra but in conjunction with or aspected by other planets. -

Just like Rahu, Ketu also represents illusion as both are illusionary planets but the difference is that Ketu is also the one who removes the illusion and brings enlightenment. Besides this, Ketu represents isolation, separation, spirituality,mystical world, other dimension means things related to alien world, also represents Son, Dog, Intuition, research ability, curious nature, things which we have already achieved in past life and not much concerned to perform in this life.

Libra is the 7th sign of zodiac belt, hence it represents the energy and things related with 7th house of horoscope, i.e. market place, business, partnerships, relations etc. Basically Libra is sign of relationships. Libra is consisted of another 2 and half Nakshatra named Chitra, Swati and Vishakha. Libra's lord is Venus.

Recently I have come across of the view that Rahu and Ketu don't have aspects on 5th or 9th house, for the simple reason that they are shadow planets and for aspects you need a sight not shadow. I am yet to verify it on at least 50 charts, so for now I will continue with traditional approach of 5th and 9th aspects of Ketu.

As Libra represents the relationship aspect of life and Ketu represents isolation/separation, this position of Ketu in Libra suggests someone who is not finding true happiness in relationship. Now, it not only includes the relationship of husband-wife but it also depends on which house Libra is going in a particular horoscope as per the Ascendant. Wherever Libra is in our horoscope, we tend to deal with things related with that house in a Libra way, means by maintaining a sound and peaceful relation and then having Ketu there will isolate you from any desire of having good relationship there.Like, if it is in 5th house for Gemini Ascendant, person will be unwilling to have kids or deal with kids or love interests. If it is in 8th house, person will scarcely interact with in-laws. If it is in 9th house, person will always find something missing with teachings of Guru or Father and that will isolate him in dealing with Teacher and Father. If it is in 3rd house, relation with younger sibling may be isolated/separated one. So, it all depends where Ketu in Libra is falling in a Horoscope to decide what area of relationship may be impacted. It also depends on Venus position as Libra lord to decide how Ketu in Libra is behaving. If Venus is exalted, person may be keeping a very good relation with everyone. Same goes with Business Partnership and other legal bindings and agreements, these people are not too inclined to get into all this and even if they go into business, they prefer to do it alone rather than in partnership. So, a tricky position and lots depend on the house position and Venus position.

Things which may impact Ketu's effect in Libra are obviously different Nakshatras Ketu may be positioned. If Ketu is in Chitra Nakshatra, then Mars will impact Ketu's results. If Ketu is in Swati Nakshatra, then it is impacted by Rahu. Similarly, if Ketu is in Vishakha Nakshatra, then Jupiter's position will be key factor.

As I said sign-lord wise, Venus is lord of Libra. So, Venus will have highest say in what result Rahu can give.