Rahu … 

Nature includes:

Tormentor, thug, liar, cheater, revolutionary, never satisfied, duality- good and bad, suddeness in action like lion who hunts and lazes by moving slow

With Mercury:

Wit, verastility, quickness, communication

Contrast to mercury it is Intuitive part of intellect

With Mars:

Becomes nore aggressive, Revolutionary

With Jupiter: 

Wastes energy as Rahu is lawless and Jup is Law

With Sun:

It is artificial of sun, Strong enemy of Sun

With Moon:

Negative Moon, illusion, paranoia

With Saturn:

Rahu is Saturn but is sudden in nature
Rahu is

FRIENDLY: To Mer, Ven, Sat

Neutral: Jup and Mars

Enemy: Sun and Moon
Rahu is 

Tamasic, brings suicidal tendencies, provided opportunity fir growth where it is placed in Chart
SIGNIFICATIONS:

Thug, smoke, intoxicants, poison, insects, owl, southwest west direction, Rahu represents north lives in SW, media, actor, comedian, magician, hunter, Blackmailer, criminal, Don, sexually deviated, sexua disease, AIDS, divorce, loss of limb/eye/body part in an accident, Trance States, Smoking, Cigarrette, Alchol,Mysteriuos, Illusion, Confusion, Maya, Clouds, Mining, Petroleum – black gold, Panchdhatu, Repitles, SNAKES, Pharmacy,Polio, breathing disorders, suicidal tendencies, lunacy, dals, oils, pitcher plant, jasmine, raat rani, all flowers BLUE incolor, bush , DuRva, paan, sauf, astringent spicy foods, all clothes below waist, black blanket, sail, satin, synthetic flashy fabric, Gambling, Stocks, Lottery, mass pschye, follower of what masses do blindly, all types of photography,video games, creativity, inspiration – lightening flash, manic depression, Bizzare vications, Anything Foreign, shadowy, secret, prophets, seers,, IT, Languages, english language, death of partner, manual labor, hunger, obese, great physical strength

Paternal Grandfather and Maternal Grandmother 

Intution, electricity, research, discovery. All types of flying machines and jobs, Sky, ALWAY FUTURE LOOKING, Suprise, mysterious, maya, sudden rise or sudden fall.

Rahu is 2 sides of same coin. Positive as well as Negative.

OWN SIGN: Aquarius (11), Virgo (6)

Exaltation: Gemini(3), Somesay Scorpio

Moolatrikona: Scorpio (8)

Debiliated: Sagittarius (but not as bad)

As Closely related to Mercury and Saturn
ASPECTS: 

Consider only 1st, 5th and 9th aspect

7th aspect do not consider as it already has Ketu
MODE OF FUNCTION:

* Retrograde

* 18 months in one sign

* Acts Like Lion or Elephant (sometimes mad) and has surprise element
TIMINGS:

* Acts in Dakshinayan

* Active at sunset and late nights 

* Major Period: 18 years

* Strongest in Dakshniyan, when moon transits on its Nakshatra- Ardra , Swati, Shatabhisha

* Days: Wednesday and Saturday 

* Rahu related to ashtami (8th) and Panchami as relates to snakes

* Matures at 42 years

* Important years of age for Rahu: 19, 38, 57, 76.