Well that doesn't really goes in here(remember this is the Action Sequence thread),
But i will explain it to you the reason the metal god/slime receives so little damage is because their extremely high defense stat, you can do an enemy like that simply by(while checking your actors stats so it's not exaggerated according to you character stats) maximising said enemy defence, this however, can turn into a problem if you don't know the exact numbers the formula will return, RPG MV will return 0 of damage for any negative number,you can, however, alter the damage formula so it always deals at least 1 point of damage.
Math.max(a.atk * 4 - b.def * 2, 1)
I don't remember the code to check for criticals, but even with the above damage formula the critical hits do about 20-30 of damage to an enemy with max def, and to do at least 2 points of damage to one the enemy you can add.
if (a.hasWeapon($dataWeapons[5])) {Math.max(a.atk * 4 - b.def * 2, 2); } else {Math.max(a.atk * 4 - b.def * 2, 1); }
however you willhave to add it to all skills, so it will get tedious after a while.Again sorry,I'm sure there is another way of doing it but my javasxript knowledge is very small.