I have a build that can defeat Callagdra and The Dread, but will be deleted one shot by this version of Tempest Spawn.
After checking monster database, I then understand what was the cause.
The rock skill throw here (Tempest Spawn - Grim Dawn Monster Database) deals base 5000+ physical damage + 2468 fire damage, taken into consideration of attributes it might mean close to 30k physical damage or even higher?
Dread + Callagdra have single hit with under around 2000 physical damage, as a comparison.
In 1 vs 1 scenario its not big deal, because it is easy to dodge, but when in Tempest totem scenario, the rock can come from any place that this fire giant is hidden.
And seems only this fire Tempest Spawn hits this hard, is this intentional?
Again as a single boss (or limited number of mobs scenario) it is a fair design, it causes issue only in Tempest Totem scenario due to monster attacks readability problems.
Roughly, you add to the original attack skill the flat damage bonuses from the passives entry matching the damage type and then multiply by the % damage bonuses on the same listing. You also need to take into consideration the extra % bonuses added by attributes like Cunning or Spirit depending on the attack type.
It’s not the throw that’s the issue. It’s the physical damage part of it and it’s pretty universal to all mobs dealing a significant part of their damage as physical (see also: Lucius, or how Ravna had to be retuned).
That said, if I recall correctly, the Fire Giant has already been tuned for its damage to be more appropriate.
However, overall if there is a problem with burst damage (either a single hit or a shotgun), it’s largely due to the attached physical damage.