Question on damage type caused by spells

[WhYdOyOuThInKtHaThApPeNeD]

I can't tell by the in game info exactly what type of damage many spells are doing for sure.
Are they doing magic type damage or other?
The translated manual helps a lot but just to be sure if anyone can confirm...

Example:

Fiery Rain: is doing purely fire damage or magic damage type? So units with magic resistance are not resistant to Fiery Rain, only units with fire resistance?

Is Hell Breath adding a different type of damage done by the units it is cast on? If the Green Dragon has Hell Breath cast on it, so it is doing it's own damage type as physical + the bonus added by Hell Breath is fire or magical? Or is it just increasing the damage type the creature already has. So on Green Dragon it gives physical type bonus, but on Red Dragon it gives fire type?
It says "fiery loss" in the manual so I assume it adds fire type damage to any unit.

Geyser: is it doing purely physical damage, or is it magical damage. So units with physical resistance are protected from Geyser?

I see in the manual it says "Total loss" so I'm thinking that means the damage done by the spell is 100% of that type of damage given.

[DGDobrev]

Rather than responding here, I've decided to compile everything in a post in the info thread, because your question is very valid. Here's the link for you:
http://forum.1cpublishing.eu/showpost.php?p=143958&postcount=35

[WhYdOyOuThInKtHaThApPeNeD]

Fantastic, thanks!

[BB Shockwave]

So, Ice Snake does physical damage? I always thought it'd be magical, considering cold damage is usually magical. I wonder how it works then against cold resistant units like Polar bears, who also have physical resistance?