Summary:

Visage's gravekeepers cloak armour/magic resist is removed after all elements of an attack (i.e. if you have sticky napalm on him they both get reduced as if he had all 4 stacks up)

Repro:

1) Create a visage, level to 25, 4 levels into gravekeeper's cloak
2) Create a batrider, level to 25, 3 (THREE!) levels in sticky napalm and give yourself a shivas.
3) Cast 10 stacks of sticky napalm on visage (or 8 if you screwed up step 2 and got lvl 4 sticky napalm)
4) Cast shivas on visage and observe the combat log

Result:

Sticky napalm & shivas do the same amount of damage.

Expected result:

1 part of gravekeeper's cloak is removed between each instance and therefore you deal more with sticky napalm.