I like this a lot! The expressions exchanged between the characters are very clear, and the poses are nice. I also like Fyn's design, he's a very distinct character
There are only two things I would like to mention for constructive criticism.
The background is very interesting, and I particularly like your color choice for the sky, but I'm a little thrown off by the bold black line outlining the rock that they are standing on in the foreground. It is very dark and thicker than the character outlines, which makes it a bit distracting. I would suggest using a different color for the line, such as grey, making it thinner, or not using it entirely.
Also, Fyn's tail is very close to forming what is known as a "tangent" with cera's back. This happens when lines intersect in a way that confuses the eye, so it's hard to tell which is in the foreground and which is in the background. For something like that you could change the posing so that Fyn's tail is slightly lower and overlaped by Cera's back, or slightly higher so that the eyes are not drawn to the line intersection, and it more clearly appears that his tail is receding.
Hope that was somewhat helpful! If not, sorry
