A great continuation from the first novel and a great ending. The ending does raise some questions which could be explored in a companion series, but time will tell if it gets written.
The main ding I have is I found the stakes got lesser when

the group traveled back to the Ether

. I would've liked to have seen more

of their powers going wack on Earth

before then, but that's alright.

The ending does leave open with what happens to Gem using the seventh shard, but that's an answer we probably will never get.

And that's okay.