@ECMO3 With regards to Earth Tremor, you are missing what @Sacrosanct is saying:
Without Circle Casting, the spell has a range of 10 feet, and the effect applies to the entirety of the area within range.
But, with the Augment option of Circle Magic, which only requires secondary casters to...
This may or may not work, depending on how the multiple cubes aspect works (or doesn't) with the Expand option.
This doesn't work because you cannot Circle Cast cantrips, such as Sacred Flame.
As for the list of spells under Augment, they all look legal.
That actually depends on the Circle benefit being attempted.
Augment, Distribute, and Safeguard don't require secondary casters expend a slot.
Expand and Prolong require expending a slot, but it doesn't list a minimum slot requirement.
Only Supplant requires each secondary caster to expend an...
I haven't watched the video, but either it or you makes a big error: Not just anyone that can cast can be a Secondary Caster. To quote:
"A secondary caster must have either the Spellcasting or Pact Magic feature to participate in a Circle spell."
Spellcasting as a result of species...
Both books mention where they can be found, but neither details subtypes or traits. At best, Heroes says that they tend to be like the Giants in the area they reside (extrapolated example: Fire Giant Goliaths residing atop Mount Neverwinter).
@JPL I should have been clearer about that, sorry.
Not much. There is mention of Orc myths involving a rivalry between Gruumsh and Corellon. There is also a mention that Orcs came to Toril from other worlds, with a legend that Faerun was divided among the various species, there was no more room for Orcs to have their own, so Gruumsh declared...
No specifics on subtypes in Heroes of Faerun.
Adventures does mention Goliaths for a number of places, but still not much detail on them, there, either.
From SCAG:
"For a time, living mages couldn't hope to advance to prominence in Thay: Szass Tam promoted undeath as a means of existence with boundless possibilities, and held back those who didn't agree with this philosophy. The recent battles with the demon Eltab, however, have prompted Szass...
@TravDoc42 @Parmandur
Perhaps tying into the backstory for the movie Honor Among Thieves?
Maybe the rise of Szass Tam was violent enough to require reconstruction?