Jupiter in 8th House synastry relationships are formed on the basis of financial and business activities in those life spheres that are of mutual interest for the partners: joint-stock companies, funds, banks, etc.
In a marital relationship, family well-being occurs after converging the capital and its skillful usage, which usually means smart investing, both long- and short-term. The Jupiter in Eighth House synastry partners very aptly manage their common affairs and constantly strive for success.
Curiously, their robust business activity does not prevent rigorous involvement in spiritual and religious life. The partners may have a lively interest in the occult and esoteric studies, reincarnation, and eternal questions of the immortality of the soul.
If Jupiter is negatively aspected, lies, self-interest, scams, and deceptions creep into the relationship of partners.
from F. Sakoyan, L. Ecker
Jupiter in 8th House Synastry Explained
Jupiter in 8th House synastry partners tend to think that they play a big role in your life — or will play it at some point in the future. This may or may not happen, but if we are talking about things like career advancement or coming across other exciting opportunities, they are more likely to happen with this partner rather than with you.
As far as the role of a generous benefactor is concerned, a Jupiter in Eighth House synastry partner will be able to play it only after an in-depth analysis of your circumstances, both external and internal. However, any unprepared attempts to do you good in difficult situations can lead you to hostile emotions and suspicions of insufficient purity of the partner’s intentions, especially the desire to assert him- or herself at your expense, to which you will react extremely negatively.
At a low evolutionary level of the Eighth House, any obvious superiority of this synastry partner over you, no matter whether in the material or subtle planes it occurs, will cause you a storm of indignation, jealousy, envy, and other similar feelings, which, however, can be temporarily displaced into the subconscious in situations when certain benefits coming from the partner are going to fall into your hands ready for consumption.
In reality, however, this is unlikely, and the rich inheritance you are counting to obtain through your Jupiter in 8th House synastry partner may well float in a very different direction, including the people whom you specifically wanted to leave out of the picture.
It is very important for you to understand that your relationship with a Jupiter in the Eighth House synastry partner is primarily about ethics and responsibilities to the world, and only secondly about finances, prosperity, and opulence. Thus, if you focus on the former, the latter should follow on its own accord.
from A. Podvodny