Doedre Darktongue: Why EE doesn't lower her fire resistance?

Doedre Darktongue http://pathofexile.gamepedia.com/Doedre_Darktongue
Under her name it Fire resistance unlike most bosses which have all elemental damage resistances.

But when used a cold skill while having Elemental equilibrium on character, it changes to
1. Fire Resistance
2. Cold Resistance
3. Vulnerable to Lightning

When used Lightning skill with EE, it changes to
1. Fire Resistance
2. Lightning Resistance
3. Vulnerable to Cold

Why is her Fire resistance uneffected by EE?
Other bosses shavs/maligaro works perfectly fine with EE, so does Mr. Malachai the nightmare.

It is affected just fine, it's most likely higher than 50% so when you use EE she will have some fire res left over, and as long as it's higher than zero she will have 'fire resistance' line. Try using flammability and ele weakness to push it below zero.

I say 'most likely' because she's a strange boss, curses on her don't last as long and she might have curse resistance beyond what normal bosses have because curses are her thing. Equilibrium isn't a curse, but it's possible she's resistant to that too, as a special case. Unfortunately, we won't know for sure until devs tell us.

Ah that makes sense, I'll try to self cast flammability on her to see if it changes next time.

its currently on my cwdt & linked to golem :P