I should say this; Berserk is my favourite anime/manga, so I have to say, right away, this is a great tribute to the series.
The style is really unique; it seems less a painting and more of a mix of art and physicality. The characters seem to be coming out of the image, which brings even more dark realism, fitting for the Berserk franchise.
The border is incredible. The twisted tree is very reminiscent of the tree beneath which Guts was born, and the use of light within the border is brilliant. The darkness on Guts side and the brightness about Griffith. It is very fitting and in keeping with the characters. As for the Behlit and Brand, well I have to say that your realism and paint blend is chilling. You've captured the fear and horror that they symbolise perfectly. The Behlit's eyes, I find, are the most terrifying. I don't feel comfortable looking at it, that's how good it is!
Now the characters themselves.
Unlike a lot of artists, you're not showing them in battle and for that reason, I must say that you've managed to successfully capture their 'look'. Guts is as ever uncaring but intense. As for Griffith, the less about that look the happier I'll be! Okay, my abject fear of Griffith aside, you have made him...beautiful(?). Their eyes are perfect too. Griffith has his Eyes of the Hawk, and they are chilling, yet they are strangely attractive. He looks like Griffith would in the real world. Scary, creepy, handsome and captivating.
As for Guts, bloodstained, grim of face and that damn pose! His eyes are dark and intimidating and his sword. He is great. Also that gaze. He is Guts through and through. He looks just as he should, having cut his way through the field and coming to the camp. He looks badass and captures his pure willpower. He looks almost as intimidating as in the manga when he's going up against Zodd!
Okay, for the minor points.
The metals are done well, with a convincing reflective sheen. The background is also good. Griffith, the halls of a castle and Guts the outside world. It does refelct the nature of the characters.
Okay, now for the criticisms. None. Just a couple of fanboy ones. Like the fact that it looks like Gut's sword is the Dragonslayer, yet he's part of the Hawk's, by the clasp. Yeah.
In conclusion, it is a great piece of work and I really like Guts. I hope to see more of your work on Berserk, like Casca and the others.
Only, please DON'T DO THE ECLIPSE! With your dark style, you're likely to drive us mad with terror. It would be a beautiful piece, but it'd give us nightmares.
I'm looking forward to seeing more.