Well, this is the snippet section and code doesn't get any smaller than this

Basically, when using the Dark light and fighting lesser demons, the sword will always hit 15 + a random amount between 0 and 20. Have fun :D
if(plr.playerEquipment[plr.playerWeapon] == 6746 && (npcs[NPCID].npcType == 82)){
hitDiff = 15 + misc.random(20);
}NOTE: With this code I'm sure you could work out how to make certain items super effective against a certain monster, or certain monsters, to add multiple NPC id's follow the below routine.
if(plr.playerEquipment[plr.playerWeapon] == 35 && (npcs[NPCID].npcType == 1 || npcs[NPCID].npcType == 2 || npcs[NPCID].npcType == 3 )){
hitDiff = 7;
}This code causes the Excalibur to always one-hit men (Dealing 7 damage every time, the amount of HP men have!)
If it wasn't already obvious, yes this is how you can make the anger weapons hit high on the angry NPCs.