I suspect (but am not certain) that the shining holder is:
I am a shining holder of the preservatives of life, with a hilt of melded grey matter of the core and matter of the body, black as night. Flames can touch me but they can do nothing but heat the blaze inside.
The "preservatives of life" means food, which may be held in a spoon when eating. "Grey matter of the core" is iron (from the Earth's core) and black "matter of the body" is carbon, which "meld" into steel, a material spoons may be made from. Fire will not (usually) damage a spoon but will heat the contents.
If somebody uses me to come to your aid, you will find things made easier for you. In days that have passed, I was known as an embrace.
The first part is unclear, but "spooning" is a form of embrace. OP Edit: To spoon feed someone is to make things very easy for them
One has had the experience every day, that when the sun has just passed over our heads, his head goes underwater, and his world starts spinning round and round; he feels like he’s aflame.
I think this is a convoluted way of following "sun" with "dae" (from "head" without its head, spun around?) to form "sundae", which is a type of spoon. OP Edit: Not what I was looking for, this was in reference to a 'teaspoon', they stir tea which is very hot, with their head underwater. This happens every afternoon at 'teatime'.
Another of my kind is the chart of a chaotic battle, where we lost Tallanvor.
An anagram of "battle", minus a "T" for the lost Tallanvor, is "table", another type of spoon.
Another is the start of dawn ending, so every ruler treads for an arid wasteland.
The first letters ("start") of "dawn ending, so every ruler treads" form "desert", which must be a spoon for eating sand. It may resemble the more common dessert spoon. :)