Examples:

"Icon": "gui/icons/abilities/priest/iconic_projection.png"

"Icon": "gui/icons/abilities/wizard/ninagauths_death_ray.png"

While these paths can be found in the abilities.gamedatabundle,

I could not find such paths in the assetbundle unity3d folder files. I was able to find some weapons icons, but they use a myicon_s and myicon_l extension which the abilities do not. The abilities/spells only ask for "Icon" instead of Small or large such as
 

"IconTextureSmall": "gui/icons/items/weapons/miscellaneous/citzals_armory_greatsword_s.png",
"IconTextureLarge": "gui/icons/items/weapons/miscellaneous/citzals_armory_greatsword_l.png",

Which causes the evil Red X of Fail if you try to use these in the "Icon":

i'd rather not have a purple sword spell use a green berath sword icon if it can be helped.

Edited December 22, 20205 yr by anthon

I was looking for those myself recently, they're in

.../PillarsOfEternityII_Data/sharedassets2.assets

Type: Texture2D
Name: SpellAbilityIcons
PathID: 112

(note that it's a big fat sprite sheet)

Edited December 23, 20205 yr by Noqn