Doesn't a composite attack take into account both defense and mind? If so, wouldn't a character that had a million mind and zero defense still take quite a bit of damage?
Yes and no..
composite attack is like
some multiplier X ((attackers attack + attackers Magic) - (defenders defense + defenders mnd).
So let's pretend the attacker has 10k attack and mag, patchy has 20k mnd, and generic other person has 7k mnd, 7k defense.
attacker dude attacks generic dude
1 X (10k + 10k) - (7k + 7k) = 6k damage taken, oooh the pain.
attacker dude attacks patchy
1X (10k + 10k) - (0k + 20k) = 0k damage taken, *queue superman bullet deflect chest flex*.
Of course most attacks have multipliers other than 1 (which wouldn't really matter here), and divide the defense by 2, but you get the gist.