Rhysel trying to build a transfer point to her native world, despite knowing it won't work.
Revenn's death and Rhysel's inability to contact him.
We already know that Rhysel's parent hit her when she was a kid, and then in Chapter 24, they call her a freak of nature and disapprove of the same magic that we often see her using to help people.
In Silver, chapters 12 and 13. The cured shren children who fear that they're not getting adopted, each of whom has a distinct and lovable personality, are heartbreaking enough. Then in 13, when they've chosen who to adopt and Ehail is happier than she's ever been...
"There's a couple of dragons in my office, and they want Kenar."
...everything gets shot to hell.
We find out to what much extent the Mind Blast truly is once Talyn gets a way to partially treat it he never got to actually mourn Revenn
The state of Ryganaav before Talyn helping it and even worse after it