Sun in 12th House synastry – a person with increased potential of the Sun energy may help the Twelfth House person to realize their hidden potential more freely and openly. The partners are able to stimulate and develop their subconscious mental faculties. If negative aspects dominate, psychological incompatibility emerges at the subconscious level of thinking.
Otherwise, the partners can easily find common interests in mystical and occult studies. In some cases, the Sun in Twelfth House synastry can move into the sphere of subconsciously intuitive telepathy with the subsequent opening of a karmic channel. The influence of negative aspects significantly complicates the relationship in this regard, introducing elements of deception and forming hidden and locked zones in the depths of the subconscious.
from F. Sakoyan, L. Ecker
Sun in 12th House Synastry Explained
Sun in 12th House synastry is a double-edged sword that tempts your partner the most as your behavior can seem sacrificial and focused on manifestations of his or her will. You are likely to act toward this partner as if they were conductors of divine input, which is very gratifying to the partner’s ego. However, having enjoyed this role for a while, the partner can start exploiting and manipulating you.
You may not notice this initially and keep serving your Sun in Twelfth House synastry partner’s will sacrificially. But at some point her deception and inability to show you any real revelation will become obvious and the relationship will collapse, which will be worse for the partner if your own behavior was honest. However, if your sacrifices were not genuine and pursued self-interest, then this breakdown could be a disaster for you.
from A. Podvodny