If it ignores electrical resistance/immunity, why bother making it electrical in the first place? Just have it be Profane damage, which has no resistance/immunity...and make it literally 'Evil Rain' in the process. Electric rain would make sense on an Abyssal plane, specifically since it is something Tanar'ri are immune to and thus wouldn't notice any worse than regular rain, but the need to make this specific aspect of the weather a threat to the party is causing some weird logic loops.<br/><br/>Also...those umbrellas must be the most badass artifacts in existence, if they can block/deflect all of those damage types and are the only things that can do so. It would honestly make a lot more sense to have Profane rain, and the native creatures to have evolved Profane resistance that carries over into their hides.