https://www.amazon.com/Andalite-Chronicles-Animorphs-K-Applegate-ebook/dp/B0793F4XXD/ref=sr_1_6?dchild=1&keywords=animorphs&qid=1624879468&s=digital-text&sr=1-6

The Andalite Chronicles were, I think, an offshoot of the animorph franchise that I read as a kid. The only thing I could remember was the blue cenetars that talked through their minds and ate through their hooves. I don't know if it matches the rest of your boxes but I think this is the right book.

The Andalite Chronicles (1997) by Katherine A. Applegate was, I think, an offshoot of the Animorph franchise that I read as a kid.

His name is Elfangor-Sirinial-Shamtul.

An Andalite war-prince. The one who gave five young humans the ability to morph into any animal they touch. They are still out there, fighting an evil so powerful there isn't a moment that goes by when they can actually feel safe. Their story continues.

But this is how it all began.

The story that came before Animorphs . . .

The only thing I could remember was the blue centaurs that talked through their minds and ate through their hooves. I don't know if it ticks the rest of your boxes but I think this is the right book.