2nd post of 2nd book

"Eragon stared at the dark tower of stone wherein hid the monsters who had murdered his uncle, Garrow.
He was lying on his belly behind the edge of a sandy hill dotted with sparse blades of grass, thornbushes, and small, rosebud-like cactuses. The brittle stems of last year's foliage pricked his palms as he inched forward to gain a better view of Helgrind, which loomed over the surrounding land like a black dagger thrust out from the bowels of the earth.
The evening sun streaked the low hills with shadows long and narrow and- far in the west- illuminated the surface of Leona Lake so the the horizon became a rippling bar of gold.
To his left, Eragon heard the steady breathing of his cousin, Roran who was stretched out beside him. The normal inaudible flow of air seemed preternaturally loud to Eragon with his heightened sense of hearing, one of many such changes wrought by his experience during the Agaeti Blodhren, the elves' Blood-oath Celebration.
He paid little attention to that now as he watched a column of people inch toward the base of Helgrind, apparently having walked from the city of Dras-Leona, some miles away. A contingent of twenty-four men and women, garbed in thick leather robes, occupied the head of the column. This group moved with many strange and varied gaits- they limped and shuffled and humped and wriggled; they swung on crutches or used arms to propel themselves forward of curiously short legs- contortions that were necessary because, as Eragon realized, every one of the twenty-four lacked an arm or a leg or some combination thereof. Their leader sat upright upon a litter borne by six oiled slaves, a pose Eragon regarded as a rather amazing accomplishment, considering that the man or woman- he could not tell which- consisted of nothing more than a torso and head, upon whose brow balanced an ornate leather crest three feet high.
'The priests of Helgrind,' he murmured to Roran (Paolini 1-2)."

I think that this passage is setting because of how the author uses a lot of describing- giving the reader an idea of the place where the main character is and what he's doing, what he's seeing; etc. For the most part, I think Paolini gives an almost constant barrage of information, constantly describing- which makes the story all the more interesting. The pages following this passage are somewhat graphic- the priests and the others attending in the procession come to a halt at an alter and there they drink each other's blood calling upon themselves to become servants of some sort to their 'Great and Terrible Lord (Paolini 4).' The reader assumes that the 'great and terrible Lord' is no other than Galbatorix or someone else that Paolini hasn't introduced the reader to yet that's just as powerful as Galbatorix.

Questions: What would make these people do this? What would make them want to be like this? What is Galbatorix up to? Is humanity really this horrible? Strange that the author uses this as an example of the atrocities that people commit everyday... Wonder why he did that?

Note: For some of the spelling, such as "Agaeti Blodhren" I didn't have the proper keys to put the right enunciation marks where they should be (according to how they're found in the book).
-katthegreat08