[1.2.276] More rebalancing

I doubt it's hard to change the current Onyx Apple's +100 mAtk into +150% mWatk (1000 magic attack would become 1500).
Raw numbers, like + 500, would cause chaos for low leveled mages.

Just like how onyx apples cause chaos for low leveled weapon classes?

Making a % increase would mean that regular +m.att pots would stack with it though...