i know it's late.. but if you still don't have an answer, I tested with my conqueror
battle standard: 45% damage absorption
colossus form: 66% damage absorption
i removed all items and only wore thoths glory and SB cuffs both to get as high %damage absorption as possible and to render the +1 to skills from battle standard moot.. then i tested against the staff attack of the first boss in Helos.. the staff attack only to make sure armor and DA don't mess with the damage taken
while testing, i just found out that the show damage is bugged.. it doesn't consider the reduced damage caused by damage absorption..
and probably also doesn't consider resistsso i had to do it by eye test so my own test is crude also.. but i took pics to make it a little more trustworthy.. 2x each
notice that the damage shown all shows 1097 but if you look at my health, clearly it's not all 1097
items and skills:
1st pic is from full health with no battle standard and colossus form.. it shows 1097 but clearly i took more than that
next is with battle standard only.. it still shows 1097 but clearly the damage taken got reduced
next is with colossus form only.. colossus form itself raises health by 66%.. i'm taking less damage now compared to battle standard
last is with both colossus form and battle standard active.. this time i'm taking volcanic orb damage as well.. and i also quit and restarted cause colossus form CD is very long.. so maybe that's why it's saying 1227.. i'm taking considerably less damage but not immune (around 200 each hit)
all these were done with full health first, then after i get hit with 1 staff attack, i immediately take a screenshot
so with these,
i think i can say %damage absorption is multiplicativeactually, i read this a few days ago but there was about 2 weeks where i couldn't play.. and then after that i got sick for a few days.. i tried a little bit after that but saw TQ very laggy so i lost interest.. only now my curiosity finally won
edit: just to make sure, I made another test with colossus form only.. this is with the same seed as the 1227 damage
clearly i'm taking more damage here than with both colossus form and battle standard active