A few quick thoughts:
- I liked the idea of the introduction. Having a royal assassination take place on the night of the heirs' birth is a nice touch.
- I thought that your use of tension was excellent, and it created a nice emotional scene.
That said, I would not have kept reading, for the following reasons:
- Grammar. I'm not going to get tied up over an individual typo or screwup here and there, but there were enough grammar problems that the text was genuinely hard to read. The errors included dependent clauses that needed commas but didn't have them, run-on sentences, and clauses separated from the object they are modifying by enough distance to make understanding the text problematic. This needs a strong copyedit.
- Style. Another critique said that your novel felt padded, and I agree with that. For example:
"To him the birthing of the twins seemed to be taking a lot longer than what he thought was necessary."
If it "seems" to be taking longer than what "he thought" was necessary, then it is automatically something that applies only "to him". You could have used just one of these phrases.
"Now it sounded like the rest of the royal palace outside of the birthing room was being attacked."
If an explosion has just rocked the building, we can understand that it's being attacked. We don't need to have this explained to us this explicitly.
"The tall stern faced Krannion knight commander and champion of the royal family, moved towards the door and slowly opened it, his hand tight on his proctors’ sword hilt."
Aside from the grammatical errors here, there's too much information. I don't know what a Krannion person is, but trying to absorb the fact that he's that, and also tall, and stern-faced, is too much for just one line. Then you add that he's also the knight commander and champion of the royal army. Then, when you actually get to the action, you explain it in too much detail. Noting that he moved to the door might not be necessary. Noting that he opened it slowly might not be necessary. Noting that his hand was on his sword might not be necessary. I can see using one or two of these notes, but you're trying to pack too much into the sentence, and as a result, the sentence loses a lot of the power it might have had. Most of the time I've seen this, it comes as a result of the author not trusting the reader. If you tell me that "The king's champion eased the door open, his sword ready," I understand that he's someone important, and that he's moving slowly and cautiously, and that he's probably got his weapon held tightly.
"The ringing sounds of swords on swords and metal on metal signified a battle being fought outside. The sounds of it filled the birthing chamber. "
You didn't really need to mention the swords here. I liked the ring of metal on metal. You also didn't need to mention that it signified a battle being fought outside, as the reader probably gets that. You could simply have gone with, "The ring of metal on metal (or steel on steel, or whatever) filled the birthing chamber."
There are further instances of this sort of thing (the villain's line was similar, in that I thought you took a cool moment of betrayal and overexplained it, possibly afraid that we wouldn't understand that this guy was turning on his brother), but you get the idea. It's great that you have such detailed pictures of what's occurring -- in fact, I think that's one of the only ways that good text can happen. But I think what's breaking down is the process by which you come up with the cool, complete image with all the description, and then figure out which elements are absolutely vital, and are in fact so good that they let the reader paint the rest of the picture for themselves. Sometimes it might be necessary to explain to the reader that a character is tall, or how he is moving, but other times, you can just go with the important information and trust that the reader will fill in the details, either with what you wanted or with what the reader wants to visualize when he pictures a grim royal champion.
On a secondary note, this might be part of including too much information, but your sentence lengths were very close most of the time, which makes it tough to absorb your writing. If you think of it like the martial arts you practice, you don't always want to throw a big reverse punch, right? Sometimes you want to do sharp little jabs to set them up for the big reverse punch, and sometimes you want a hook, and sometimes you want to get in close and tangle things up a bit. If you vary the lengths of your sentences and paragraphs a bit more, you'll have an easier time hooking readers into your narrative.
- Telling instead of Showing. This one is murky, and it's like passive voice for me, in that a lot of teachers will flatly say "Never use passive voice" and "never tell when you can show," but really, you have to pick your battles. Sometimes passive voice is the right way to go. Sometimes it isn't. Sometimes you need to just say what happens instead of going into detail, and sometimes you need to go into more detail.
For example, when Bertravis kneels at his king's feet and swears and oath, that's something I want to hear. That's a cool badass honor moment, but you glossed over it. There are other instances like this, and I suspect that you might have done this because you were concerned about the pacing of your scene. Fortunately, if you cut out a lot of the additional stuff I mentioned earlier, this scene will be a lot shorter, and you'll have time to zoom in and actually say what Bertravis said to his liege, and what Bertravis said back to him. In fact, if you do that, you can get rid of even more, as the dialogue will imply a lot of what's going on elsewhere.
Overall, I know that style isn't as important as story structure when it comes to novel plotting, but in this case, the style hit me at the point where I wouldn't have wanted to continue. Since this sold to a publisher, I'm assuming that you had a decent story structure, and that means that in your future works (since this one is out, I don't imagine you'll be editing it), you can keep the structural strength you have going and make edits to your story after you've got the first pass written in order to tighten up the scenes and give yourself more room to handle some of the big cool bits that you didn't feel like you had room for in the first pass.
Good luck!