Mercury represents communication, Cartesian and logical spirit.
Mercury in Leo
Ambitious, sincere, loyal, friendly and full of good cheer. Great sense of organization. Likes children and leisure time.
Weaknesses: likes to play games too much and can go too far, in spite of himself. Likes to play-act and do about-turns, which surprise and upset those concerned. Likes to take risks in jest and for amusement.
Mercury in VIII
Has a fear of death, but who doesn't? He can be tormented at night. He likes research, investigation, enquiries. Studies well.
56 Sextile Mercury - Jupiter
He is intelligent, has big ideas: he is tolerant and has a strong sense of justice. He has good judgement, good sense and has his feet on the ground. He has the "gift of the gab", and likes to speak, he also likes literature. He is erudite and will normally be successful socially.
73 Trine Mercury - Saturn
3 Trine Mercury - Ascendant
He is intelligent, with quick and lively reflexes. He is preoccupied by his circle, likes to exchange ideas with his friends, but also with strangers. Of an open nature, he goes out to others.