I'll give you some feedback in
@Eldoria's stead, that way, they can have their much-needed respite.
So, the overall vibe I get here boils down to a "meh". Meh in that it is neither good, nor bad. It has good moments, bad moments, and a lot in between. It is neither a stand-out scene, nor does it fall flat on its face.
I think the biggest thing hurting it is that it is an isolated, one-off scene, and because of that, you stuffed content into it that didn't really need to be there. Alternatively, if I am mistaken, and this is actually part of an ongoing story, there is content misplaced and it is harming you, especially at the beginning.
I can't copy paste it, so giving examples is a bit tricky.
However, there's the two paragraph bit about his father's beliefs, a bit about the Saintess, a little more content on the crowd, and more regarding Phila and Esther, as well as other noteworthy individuals.
These bits take the wind out of your sails. As action begins rising, building up, you have added details that sort of set it back and would be better placed well-beforehand or after the scene entirely.
On a more positive note, once you get to the actual bout between these two duelists you take off. There's no more of this interrupting exposition. The dialogue is a tad clunky here and there, but serviceable. The momentum and cadence of the scene is good. The general concept behind it is good. A put-them-in-their-place scene is a classic of shounen stories, so having one in yours is a good thing. It also establishes that your protagonist is clever enough to pull something like that off.
I think one thing holding the action back is the lack of descriptions. We get a little bit, but I'd say trying to get about 20% more visual would go a *long* way. So, a little more detail on how they move, act, react, etc., especially when the tides turn and Eric takes the lead.
We just get the beep, beep, beep and can assume he's making clean strikes, but even a single sentence describing what he's doing, and how, here and there would be a massive improvement.
So, yeah, I think it's a decent scene, but nothing that will stand out in the grand scheme of your story as "that was my favorite scene". However, it has the groundwork laid for a really good action scene, so dabbling with it, refining the presentation, organization of information, and adding a liiitle more detail to the actual action will bring it up from "meh" to "heck yeah!" in short order.
You seem to have the writing chops for it, too, so its just a matter of going back, looking it over, really trying to visualize it yourself, and then put what you see onto the paper.