Rahu: effects and importance in Indian astrology

Rahu is considered an imaginary planet in Indian astrology; Rahu is instrumental in strengthening the power and can convert enemies into friends. It is popularly called the Planet of Success. Even the effect of snakebite could be removed by his grace. Success of effort is a blessing of Rahu as he stands for vigor and valor. It is a node positioned at the meeting point of earth's trajectory around the Sun and the Moon's trajectory around the Earth. Rahu is believed to represent the head of the demon. When Rahu, Sun and Moon are in the same zodiacal longitude, solar eclipse takes place. Being a Malefic Planet, it rules over thieves, witches, magicians, venom and poison, snakes and thorny bushes, jails and isolated places, unanimated places, hypnotists etc.
As Rahu is not a real planet, it does not rule any zodiac sign. Rahu is a shadow planet. On the positive side, the influence of Rahu can put us in harmony with collective trends and give popularity, prestige, fame and power. Rahu can give psychic powers, but also there may be danger from drugs, and danger from black magic.
Saturn is known as serpent and Rahu and Ketu as its head and tail respectively. As a node of Moon, Rahu shall not provide adverse results. So long as 4th house or moon is not afflicted. It gives good results when Mars occupies house 3rd or 12th or When Sun and mercury are in house 3rd or when it itself is posited in 4th house.Rahu further provides good results if placed together with mercury or aspected by Rahu.
Rahu offers highly beneficial effects if placed in houses earlier than Saturn. But if it is otherwise, Saturn becomes stronger and Rahu acts as his agent. Sun provides very good results when Rahu is aspected by Saturn, but Rahu gives the effects of a debilitated planet when Saturn is aspected by Rahu.
Rahu gets exalted in houses 3rd and 6th whereas it gets debilitated in houses 8th,9th,11th .12th house is the permanent house of Rahu and it proves highly auspicious is houses 3rd , 4th and 6th .Saturn, Mercury and Ketu are its friends, whereas Sun, Mars and Venus are its enemies. Jupiter and Moon are neutral to it. If Sun and Venus are placed together in a horoscope, Rahu generally provides adverse results.Similarly, Rahu can provide bad results if Saturn and Sun are also combined in a horoscope. Here mars can also become malefic. If Ketu is placed in houses earlier than Rahu, the Rahu provides bad results, whereas ketu’s effect would be zeroed.
The house where a Rahu tenet becomes foreign and suffers the stigma of being unwelcome in its environment very often. So Rahu in the first is hard on the person themselves, making them seem odd, outcaste, a little too unique etc.However, they can therefore be the source of something new and original. They are often leaders of innovation in some way. Look to where the lord of the house of Rahu has gone to understand how he is reacting to Rahu, you where the lords personal interests lie, and it might give a clue as to why Rahu has attacked that Particular house.