Ouuuu I’m such a sucker for mercury-Pluto natives. To me, this is one of the most seductive placements a person can have in a natal chart.
Mercury opposite Pluto natives often grew up in environments where speech was calculating, combative, and often used as a weapon. As a a result, these natives grow up suspicious of the motives of others and spend a great deal of time digging out the truth in others (in a detective like manner) in attempt to determine whether or not the person they’re dealing with poses any real threat. These natives often make fine detectives/psychoanalysts and are not afraid to ask questions that sting, wound, and often times lead to transformation. They can be considered to have a confrontational communication style and will not back down from any arguments (though they do choose their battles wisely, and their words even more carefully). They make amazing friends and terrifying foes. They tend to easily pick up on the secrets/embarrassments/failures of others and will often times surprise you with how much they know about you. They observe everything and very little gets past them, even if they don’t voice it.
They can be paranoid, suspicious, jealous, and manipulative at worst. They can also have difficulty admitting to when they’re wrong and can be prone to gaslighting when they feel cornered/attacked.
But their minds are intricate and labyrinth like. They guard secrets (their own and that of others) very carefully. I’d even dare say with their lives.