rulership of kendras spoiling benefics

[Basab]

if a benefic planet becomes the lord of two kendras then it suffers from the kendradipathi dosha. it reduces the beneficiary effect of the planet to a certain extent.

[Basab]

absolutely correct. the 1st lord is a kendra and trikona lord at the same time so if one of the lords is 1st lord then the dosha doesn't happen. that means mercury doesn't suffer from kendradipathi dosha when the ascendant is gemini or virgo and jupiter doesn't suffer a kendradipathi dosha when the ascendant is piesces or sagittarius. kendrapathi dosha is formed if a benefic planet is the lord of 2 of the following 3 angular houses: 4th,7th and 10th.

[Basab]

for gemini ascendant jupiter becomes a functional malefic for being the lord of 2 kendras. it's being placed in kendras or trikonas won't affect it's status of being a functional malefic but the placement in a kendra or trikona will give some good results which it won't give if it is placed in the 6th,8th or 12th house.

[Vaughn Paul]

My understanding is that kendradipati dosha only applies to Jupiter with Gemini or Virgo lagna, and Mercury for Sagittarius and Pisces. It's not necessary what house Mercury or Jupiter is located in - just by rulership of two angular houses, 4, 7 or 10 is the affliction formed. It does not apply to a planet if one of the two angular houses that it owns is the ascendant itself. Vaughn Paul