6 8 12 are dusthanas and in assembly of planets saturn is given power to make justice and punish or praise as per each ones karma thus its karmkarak also and have tendency to make people realise their real self.

6th bhav is prarabdha which is 2nd from 5th and 5th is also 12th from 6th (past sanchit karm)thus  one does the work and behaviour as per sanchit..also it is rog sthan where health suffering with our body and atma is related so saturn rules it to measure the sufferings and our deed..

8th bhav is Mrityu bhav or Ayushya bhav where sufferings from 6th bhav travels ahead converting it in longterm sufferings or cutoff the enetgies of healing also makes person detached from kutumba and bhagya(its 12th to bhagya bhav)and this bhav will decide what will be next sanchit as per prarabha of this birth..

12th bhav is open sky and nirvana where shani placed people are born with balanced purva upasana and grudges thus most people goes away from their land and people to make new self..this bhav is 12th to lagna which indicates you are born with certain sanchit and sufferings..after long term sufferings this 12th bhav will decide to birth you in which yoni??as per your prarabhada and sanchit and karma cycle..
Only shani maharaj can do all this lekha jokha of us in our soul journey..that is why dustahna is forwarded to karak for saturn as no other planet can do this job perfectly..then Rahu,ketu,surya comes in picture to decide suffeings of what way ??eg.inheritance,dosha,crime,etc..
My Gratitude And Pranam to Shanimaharaj..
Sunilee Jani Pawar..
||Astu||