Can someone tell me what Super Training actually does? Does it train IV's or EV's?

Also, when do you see the effect of them? When you level up at 100?

And how rare is the reset punching bag? I've let my greninja train in HP, Attack and Sp. Attack but I wanna buff his Def & Sp. Def.

Or does anyone have a good build for Greninja?

(pic unrelated)