Echo

Echo - is a word for anomalies that manifest themselves in the world, thanks to Voice of Whole.

Home-brewed science
Essence of the Echo is in relations of different sounds and events characteristics throughout the universe "grid". Due to Yaraga world is "blurred" across that grid, it entangles with lots of other places - not literally, but in terms of said "manifestations" and characteristics - you might say that there is "a little bit of it everywhere". Thus, what happens somewhere - might cast a little bit of a "shade" of itself in Yaraga world too, in one way or another. Might be compared with a scent - bakery is burning there, but it smells of bread in here. Sniff it for a while - and you are as-if fed...

If an event has the very exact characteristics needed to interfere with Voice of Whole and Yaraga own world - it might manifest in said world as well. Almost like a chemical reaction - but in this case you deal with sounds and vibrations.

Simple examples are there - Wretched Sun itself, Kingdom of Crooked, Singers...

Common thing to meet are manifestations of Voice among those who have no Voice of their own - which is achieved through training and Calligraphy. Most simple are parts of Sun Litanies, etched wish said Calligraphy - and, used and sung properly, it causes Voice to manifest what's etched in it. Most of the time, it resonates with Voice of Whole and tend to tell something related to the manifest that should happen - for example, those everyday-use small sticks that should emit bright light for a while, bear words of what was sung long ago for long times, during Exodus - it is bond and seen in lots of associations with like, with hope, with sun itself. And thus, sung with properly trained voice, one can cause this light to happen.

Those manifestations are static and can not be etched in just any given way - one can not simply etch something about the light across surface of a shield and hope it to shine after a slight bump. Materials, voice of one who sings, Calligraphy itself and conditions around - all those have to match to make miracles come to be.