THM Nukes and CON resistance reduction

[Verecund]

I could not find a topic on this, so I'm posting here

Regarding spells like Banish and Scourge (where damage is split amongst elements), do CON spells that lower elemental resistances (i.e. Burn, Rasp, etc.) actually increase damage from these spells? Or are they lumped into an entirely separate category when this is calculated (i.e. 'Umbral', rather than 'Ice', 'Earth', 'Water')?

[Advocatus]

All of the following is guesswork on my part.

I am guessing that ice, earth, and water are considered umbral elements, while fire, wind, and water are considered astral elements. It's just like monster families; there are different monsters that are all arcana (bombs, dolls, evil weapons, etc.), just as there are different elements that belong to the same pole (fire is astral, etc.). If you lower resistance to one element, it's either an astral or umbral element, making astral or umbral spells do that much more (i.e., using Burn then Banish).