What Powders Should I Use On My Ignis Build

(this has to do with a class build, but it's a question, so IDK what section)

Ignis has 3 slots
Snail Helm has 2 slots
Nethers Reach has 1 slot
Greaves of the Veneer has 1 slot
Scorpio has 2 slots

I want to deal thunder damage, but the thunder powder special is kinda *meh*
So also fire and earth specials?

Also I know for the 2 armor specials I'm probably going to do earth and fire, what what about the other 2 with only 1 slot