Auron like evry other character in FFX has 4 overdrives
1. Dragong Fang
2. Shooting Star
3. Bashing Blade
4. Tornado
~Spheres
1. Spherimorph boss fight,Macalania Forest
2. Besaid Village, to the right of the temple emtrance
3. SS Liki, on the bridge
4. Luca Stadium, Basement A
5. Mi'ihen Highroad, Oldroad south
Auron's spheres. Mushroom Rock Road, precipice
6. Moonflow, South Wharf
7. Thunder plains, South
8. Macalania Woods,South
9. Mountain trail, Mt Gagazet
Hope this helps