I already explained you that the 2nd and 7th houses are Maraka houses. You must know how they become Maraka houses.
7th house is a maraka house directly and 2nd house is a maraka house indirectly.
You already know that the 8th house represents longevity. And please note that the 7th house is 12th house to 8th house.
Under the principle of negation, 12th house negates the character of 1st house. You apply this principle to 8th house. 7th house is 12th to 8th house and as 12th house to 8th house , it negates the longevity represented by 8th house. It means it becomes the destructive force of the character of 8th house. Because of that , 7th house is known as Maraka house.
Also please note the following.
1. 7th lord becomes maraka planet
2. A planet situated in maraka house ( 7th house ) also becomes a maraka planet.
The above two planets, as mentioned in points 1 and 2, assume direct role of maraka planet.
For example, for Tula lagna ( Libra ) Aries is the second house and its lord is Mars. Mars therefore becomes Maraka planet for this lagna.
Next, the following also become maraka planets.
1. Planets associated with these (above) planets also become maraka planets.
2. Planets aspected by these (above) also become maraka planets.
Therefore, you can categorize maraka plaents in any horoscope like the above. The first two maraka planets are direct maraka planets. The next two maraka planets ( planets associated with and aspected by maraka plaents) are next in order.
Why second house is a Maraka house?
Under Bhavat Bhavam, 8th to 8th is 3rd house. That means 3rd house also represents the longevity as represented by 8th house. 3rd house represents this character in addition to its original characteristics.
Now, 2nd house is 12th to 3rd house and under the principle of negation, 2nd house also negates the quality of 3rd house that is longevity. So it also becomes destructive indirectly .That is the reason why it is called a Maraka house.
Here also, lord of second house and planets situated in second house are maraka planets. Again, planets associated with these maraka planets and planets aspected by these planets also become maraka planets.
For example, for Tula lagna ( Libra ) Scorpio is the second house and its lord is Mars. Mars therefore becomes Maraka planet for this lagna.
As a professional astrologer, one must keep these things in mind.
Badhaka house and badhaka planets
There are some planets known as Badhaka planets.
For all movable lagnas ( if the lagna falls in a movable sign ) , 11th house becomes a badhaka house. For all fixed lagans ( if the lagna falls in a fixed sign) 9th house becomes a badhaka house and for all common lagans ( if the lagna falls in a common sign) , 7th house becomes a Badhaka house.
For example, Aries is the movable sign. If the lagna is Aries, 11th house becomes badhaka sthana and its lord Saturn becomes badhaka planet.
Again, lords of badhaka houses and planets situated in those houses become badhaka planets. Planets associated with these badhaka planets and planets aspected by badhaka planets also become badhaka planets.
These badhaka planets are not as dangerous as the maraka planets. Maraka means killing but these maraka planets are not killers always. If the maraka period runs during the longevity ending period, then only maraka planets kill the native. Otherwise, they give some bad results depending on the planetary positions in the horoscope.
Planet of value:
A planet that is lord of 2nd and 11th houses, or second and 9th houses or second and 5th houses is known as a planet of value. For example, for the lagna of Virgo ( kanya ), Venus is the lord of second and ninth houses and therefore it becomes the planet of value.
For some lagnas, you may not find one planet owing these two houses. In such a case, two planets owning differently these two houses, together become planets of value.
But they should be together or at least they should aspect each other in the chart. They become planets of value then only.
Yoga Karaka planets
If in any chart a planet owns simultaneously a Kendra and a Kona , that planet becomes Yogakaraka planet. It gives very good results during its sub period. For example, for Vrishabha lagna, Saturn is the lord of 9th and 10th houses, a Kona and a Kendra respectively. So, Saturn becomes yogakaraka planet for this lagna.
There may not be a single yogakaraka planet for some lagans. In such a case, two planets representing a Kendra and a kona separately, would together become yogakaraka planets . But they must be in association with each other in a sign or at least they should aspect each other.
For example, take the lagna of Aries. There is no single yogakaraka planet for this lagna. But Moon is lord of 4th house, Sun is lord of 5th house and Jupiter is the lord of 9th house. Now, if Moon and Sun , or Moon and Jupiter, lords of Kendra and Kona respectively , are together in a sign in the chart, or at least if they are under mutual aspect , they together become yogakaraka planets. During their periods, during the sub period in the main period of the other or vice versa, the they would give very good results. .