I am in-between regarding Berkut. On the one hand, he is much better than the likes of Garon, Iago, Hans, Validar, and Grima. Those five villains were cartoonishly evil and that was pretty much it. Berkut is different from those five in that he felt like a more realistic villain: realistic in the sense that he had human motivations behind his goals. Due to Rigel's standards and his familial upbringing, he's been hammered with the idea that he needs to become an exceptionally strong and capable soldier. He also wants to become the next ruler of Rigel, hence why he assists in the invasion of Zofia. When Alm comes into the picture, Berkut finds a rival and antagonist that stands in his way. At first, Berkut is arrogant towards Alm and believes he can easily beat him just because Alm is a farm boy, but with each victory Alm gains over him, Berkut becomes more desperate to surpass him. This leads to the mirror and Duma scenes, both were moments where he turned to a last resort to beat Alm.
I also have to praise Ian Sinclair for doing a fantastic job voicing Berkut. He really nailed the character's emotions well, making Berkut an enjoyable character to listen to. I also like Berkut's design, and all of his themes are among the best tracks in Echoes (his final battle theme, the Scions Dance in Purgatory, being one of my top three favorite tracks in the game).
On the other hand, I was not a fan of Berkut's relationship with Rinea. Rinea is supposed to be there to present Berkut's good side, but what we get of Berkut and Rinea's interactions doesn't really show that. Most scenes of the two involve Berkut lashing out at her (i.e. following his Act 4 battle, he screams "shut up" to her at the top of his lungs). This eventually culminates in Act 5 where Berkut does the unthinkable and kills his own lover just to strike a deal with Duma, and why did he do it? All because Rinea refused to become his empress. That really didn't put Berkut in a good light, and with all the interactions he had with her prior... yeah, it just comes to show using Rinea as a tool to present Berkut's sympathetic side didn't really work. The only times we truly see the two having a heart-to-heart aside are during Berkut's final moments (which felt forced to the point I didn't truly feel bad for his death) and that memory prism where we see how the two first met.
Speaking about Berkut's final moments, one thing that bugged me about it was Alm's reaction to it. While I enjoy Alm as a character, I find it odd that he still forgives Berkut and even grieves over his death. Berkut doesn't do
anything nice to him the whole game. What really tops off Berkut's treatment to Alm is when Berkut says this to Rinea in his final battle:
^That line speaks of
pure hatred!
Another problem with Berkut is that we aren't really shown of his battle accomplishments. Such events presented in the game could've better depicted him as a more sympathetic character by demonstrating how he has become a powerful soldier on his own merits just like how he states that his parents raised him to be. I would say this is another one of those cases where a villain could've had more screen time in certain areas to make them more redeemable.
But what we got of Berkut, we ultimately have a character who comes across as a whiny manchild. The game tries to make him feel sympathetic with the whole "he was raised by his parents to be a strong, capable warrior who must fulfill his duty" and his relationship with Rinea, but ultimately, such sympathy is lacking when we don't really see his successes nor genuine moments of bonding with his lover.
I liked Berkut better than Fernand though. To me, Fernand was an irredeemable scumbag in my eyes, to the point I felt no remorse when he died. At least the first Rise of the Deliverance DLC map painted Fernand in a better light, but it wasn't enough for me to truly take a 180 on the character.