Is the bonus from whatever you're fighting instant? Or is it like the sap curses? How long would it take to sap levels to the maximum bonus? And if i was fighting a player what's the minimum levels they need in att, str and def for it to be equal to piety and what levels for max bonus? Does it count potted stats towards the bonus?

I believe the bonus kicks in after the first hit.

 

Increases Attack/Defence by 15%, in addition to 15% of your opponent's Attack/Defence.

Also increases Strength by 23%, in addition to 10% of your opponent's Strength.

23% to your strength and 20% to your attack

Strength bonus is always the same as piety

15% of 34 = 5 so as long as you opponent has 34 or high attack its equal to peity.

 

Anything over is better then piety of course.