Stories about 3 Gems/guardians, changelings and liquid-centred swords

Question

I remember reading a book/series of books about 10 years ago as a teenager, but can't for the life of me remember what it was called, and I'd love to read it again! Here are some details about the book/series in no particular order:

• There were three gems which were looked after (one was emerald-like)
• The guardians were a human, a snake and a falcon (I think called Rexel)
• One of the books starts with a couple flying across a vast empty space with the falcon, then they crash land in a forest
• The land they crash in has a kingdom which is being fought over by changelings (who are transformed by sitting in a pool of liquid for a few days) and knights who ride winged horses. The knights also have the aforementioned liquid-core swords which if I remember rightly are quite unwieldy when first used

• the lead changeling used to be one of the princes, and when knights/people of the kingdom defect they normally elect to become a changeling and fight against the king

• the gems can be absorbed for the user to gain extra powers (e.g. the falcon becomes supersized / the king become a gollum-esque creature in a cave that could rip changeling heads off)

• there is a colony of humans on another world which lives in a large network of caves. In one of the books this colony was attached by a changeling army

That's about all I can remember off the top of my head, I can add more details if they come to me. I really hope that someone knows this series as it's been eating at me for a few years that I can't remember what the book was!

TIA for your help!

Answer 1

After more than 3 years of wondering whether I had made the whole thing up (I had been racking my brains long before I posted the question on SciFi.SE), I have finally discovered the answer to my question with the help of a Google Books keyword search for some of the details in my original post.

The series I asked about is The Singreale Chronicles, from which most of the details in my question are from book 2 (Star Riders of Ren [which incidentally is now much harder to search for given the keywords "Star" and "Ren", no prizes for guessing which popular franchise this returns a lot of results for]), and the last bullet point is the plot of book 3 (War of the Moonrhymes).

Thanks everyone who looked at my question in the hope of being able to answer it. That's a load off my mind!

Answer 2

Is it possibly the Kiesha'ra series.

From Wikipedia:

The Kiesha'ra Series is a set of five fantasy novels written by the young adult author, Amelia Atwater-Rhodes, which focus on several races of shapeshifters, including the avians (bird people), the serpiente (snake people), and the shm'Ahnmik (falcon people)

The book are Hawksong, Snakecharm, Falcondance, Wolfcry, and Wyvernhail.

Book one came out in 2003 so that would be 10 years ago.