Bala-riṣṭa » 12 Years | riṣṭa associated with Moon as significator
Yoga-riṣṭa » 20 Years | riṣṭa associated with Jupiter as significator
Janma-riṣṭa » 24 Years | riṣṭa associated with Sun as significator
Tri-pāpa and Catur-pāpa
Maraṇa Kāraka Sthāna
Other Combinations explained
Shadow of Sun etc.
Things you need to study outside of BPHS
Bear in mind that Neṣṭā Karma and Neṣṭā Graha require considerable understanding as these planets can surely give marriage and make life a wonderful experience or the converse i.e. living hell.