I'm planning to teach it purely physical attack moves (when it evolves), like aerial ace and brave bird and Ive caught a bunch with several natures like Impish, Lonely, Mild, Gentle, Bold, Bashful.
Which is the best for what I want it to do? Thanks
If you want an all out physical attacking Unfezant then Adamant is the best option.
It boosts Attack and lowers Special Attack, which is perfect for your moveset options.
Here is more information about different natures.