What's better %INT, %Damage or %Mattk?

I have 191 int added from equips and skills before % int. 16% int from equips and 230 Magic Atk with 6% Matk totaling all my items and skills. This is all without Buffs and my MW is lvl 19.

Why give numbers without buffs? When you are playing you will be using buffs.
Using the numbers you provided, supposing a monster with 25% defense, no other sources of defense ignore and that you'd have a 20 matk buff from something:

2% int translates to a 1.017 multiplier to your damage
2% matk translates to a 1.019 multiplier to your damage
4% dmg translates to a 1.040 multiplier to your damage
4 matk translates to a 1.016 multiplier to your damage
18% ignore def translates to a 1.060 multiplier to your damage