since you mentioned GMS (KvM mace), assuming you're doing bios, +12 cat ear beret (bungisngis) would be good (has reducs for the demis too (except for, chen and gertie which are demon), in addition to %damage) - depending on actual setup (total stats, buffs, gears) a +12 turkey may (or may not) be just "slightly" better in damage, but it offers no reducs;
use +9~12 superior temporal STR boots (with base STR 120); the ATK+71/78 bonus gets magnified greatly if you have high %demi-human damage gears (ex. +12 KvM mace, +12 CEB)
VIT boots are only better if your MHP is rather low that it could really make use of the boost from the VIT boots, and if your %damage from gears is not too high (ex. using 2x racial carga vs some other monster race - %damage is low in this case compared to +12 KvM mace vs demi-humans);
(not sure if RWC gears are available in thor, but the rings are the 2nd best accs. damage-wise after megs)
2x RWC rings; for each ring: gold scaraba card, VIT+3, ATK+3%, ATK+3%;
the reason to go for ATK+3% enchants instead of FS3 is because flash combo 5 gives ATK+120 already - and you want to magnify this even higher with the high %demi-human damage boosts from the KvM mace and CEB, and along with the ATK boost from the STR boots too;
VIT+10, special VIT enchant on faceworm skin; wakwak card (ATK+60/65 at STR base 120/130) is far superior than jejeling (MHP+2400/2600 at VIT base 120/130) and even better than giant whisper (ATK+20, MHP+3%)
BDM[1] with dark pinguicula (mid) + pirate dagger (low) - best all around damage
or odin mask (6%damage vs demi), or hockey mask (5%damage vs demi) (mid+low) - best vs demi-humans
other low/mid alternatives: BDM[0] + 99 red balloons (total +3 to all stats)
just note that damage differences from having various low/mid gears may not be that much so you can just go with whatever is most affordable/accesible
for costumes:
mid 1 stone (upper), ATK+1% stone (mid), physical shadow set (total refine +22), champion shoes (shadow), hard shadow armor, cranial shield (shadow) (some reduc) or VIT shadow shield (more VIT)
appropriate elemental converters, increase HP pots, STR/VIT foods, ATK consumables
do note that accurate damage maximization also depends as your base level (MHP/MSP) scales up and can affect which gears are the "true" best (in addition to the setup as mentioned before);
currently, as far as i know, the irowiki calc is your best bet for guessing damage (though not perfectly accurate, and you have to input stats/bonuses manually if a gear/card is unlisted);
or you can do calculations on your own with the (skill, ATK, weapon refine bonus) info from irowiki, and the new 175/60 base MHP/MSP tables (more tedious though)
Edited by ka10, 12 June 2015 - 07:46 PM.