Pluto in 12th House synastry relationships are based on the mutual desire to study psychology, religion and mysticism, parapsychology and meditation, issues of reincarnation. The partners may conduct collaborative research in clinics and hospitals, churches, prisons, and other places involving seclusion or forced confinement.
The “Plutonian” personality tries to influence the sensual and emotional side of the Twelfth House person through the subconsciousness to protect her from excessive solitude and losing touch with reality. In a negative scenario, this causes a violent protest and leads to a significant undermining of the relationship, as an element of latent hostility is introduced. In a positive scenario, Pluto in Twelfth House synastry partners actively help each other improve themselves, which contributes to the constructiveness of their relationship as a whole.
from F. Sakoyan, L. Ecker
Pluto in 12th House Synastry Explained
Pluto in 12th House synastry partners can become a source of your deep suffering, the result of which can be both your inner cleansing and liberation from the inert subconscious programs or deepening of your inner problems and slipping into a hellish existence. Here, the choice is yours, although the partner can adhere to the opposite point of view.
In general, Pluto in Twelfth House synastry is a tough aspect requiring not to lose your cool in the face of your partner’s ugly behavior and not be personally offended by the irrevocable losses and suffering that you will experience. As a matter of fact, any partner will cause you at least some trouble, and this is not a reason to consider them enemies or break off relations with this. But in this case, your internal reactions will be very sharp and exaggerated as the temptation to consider your partner as a secret enemy becomes irresistible, and you need to figure out, why.
Indeed, the “purges” that your Pluto in 12th House synastry partner sometimes arranges for you have an ambiguous nature and meaning that is hidden; but it is not at all connected with the enemy’s insidious plan to hard you — most likely, your partner’s actions and criticism reaches much deeper levels of your subconsciousness which, in turn, leads to more violent reactions on your part, and it would be extremely beneficial to figure out what it is that razzes you so much. Of course, to work out this synastry, your efforts alone will not do: the partner must also learn to be attentive to your changing moods, avoid provoking you further when you’ve lost control, and, above all, save his constructive criticism for the times when you are the most receptive to it.
from A. Podvodny