Mahapurusha yoga and conjunctions
I was wondering if for a mahapurusha yoga to happen, the planet needs to be alone in it's own or exaltation Rashi in a kendra house?
It depends on the yoga. In the "Yogas of Character" course Ernst goes into the details of this.
Sometimes a planet with the exalted/MT/OS planet will make the yoga void (for example, when the Moon is with Venus). Sometimes it can just indicate more work until the person can actually fully reap the rewards of that planet (for example, when Mars is with Saturn).
It cant be with sun or moon ,but it can be with other planets.
but if with rahu they have to grow into it.