Pros and cons of there respective builds, and wich one is the most powerful.

If you abuse potion stacking; neither, since you can jack things up till it crashes the game that way.
If you abuse blacksmithing and enchantment, warrior since you can create weapons that will one shot anything on master difficulty.
If you chose to not abuse anything and stick with the specific skills, warrior, since you damage scales enough that you don't magically start "doing less damage" as you levelup.