there isn't really one because, as you said, for every point you have in the mastery type thing (int/str) you get progressivly more hp/mp per point put in.
say a lvl 1, 1 point into inltellingence give you like 10 mp (guess) but at lvl 45 1 point into int will give you like... alot more MP (my highest c haracter is 15

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