I'm probably just thinking of examples from other RPGs, but I could have sworn that if you're performing an ability where you take damage as part of the ability, you can't use your energy resistance against that damage. Did I pull that out of nowhere or is it a real rule? If it's real, where is it listed?
The example that brought this up is the Apocalypse mystery for oracles, in Monster Codex page 56. One revelation, "Pass the Torch", allows you to set yourself on fire to hurt creatures around you (because they can't catch you if you're on fire) - you take 1d4 fire damage when you turn it on, and at the start of every turn you keep using it. Another revelation, "Defy Elements", allows you to gain resistance 5 to one particular type of energy. If the Defy Elements resistance works against your Pass the Torch fire damage, it seems like such an obvious choice for any and all oracles who want to use Pass the Torch that I'd half expect it to be mentioned as such!
(Unless you want to emphasise your oracle's tragic nature - as I kind of do - and the healer doesn't mind that you've prioritised story over gameplay - as, since I'm making the character in isolation, there isn't a healer so everything's okay.)