No clue if this has been mentioned already, but the amount of prints and specialized techniques on these figures is ridiculous.
One of the most detailed minifigures ever, the Silver Centurion, has close to as many prints and dual molds as these do.
These are some very nice designs (albeit Onua doesn't use the same technique Axl does in using a large helmet to fill up the gap made by the larger torso), but it must be kept in mind that this is for a Lego theme which has many limitations on what it can use.
I bring up the Silver Centurion because that was a preorder exclusive and never sold in any sets, as to point out that they've never released something with this kind of printing in a normal set.
Since this is an action theme, let's just look at a modern Nexo Knights figure.
This is from last year, but frankly there's little difference. This figure has printing on the legs, pelvis, torso, back, and head. In addition, it has a dual molded torso piece shared by every Nexo Knight in 2016.
I'm going to use Tahu as a comparison since they both have the same role of "good guy leader" in both series (unless you're completely changing the characters).
This figure has: printing on the legs, printing on the torso, printed presumably on the back, printing on the arms, dual molding on the arms (since Lego's printing techniques can't reach that far around the arm), printing on the pelvis, printing on the head, and printing on the mask. I'm not sure about printing on the sides of the legs but I wouldn't be surprised considering the entire figure is covered in printed detail.
Point being, this level of detail is not far from what Lego used for a game preorder exclusive never sold at retail (without the addition of a dual molded torso piece and printed 1X1 tile, though it could be said that a few of these figures have custom cloth parts with prints), and it's simply too much for a single minifigure sold at retail. I've nothing against most of the design choices, and I'd love to see them in a realistic form (not to mention I'd absolutely buy them, but that's disregarding the cost), but as of now they simply have too much detail for a single minifigure sold at retail.
Based on the figures of old, I think Lego uses tampography (or once did), which means that every new color is a new print and is kind of susceptible to failure. I don't have a modern example of this (though a few older ones, say, late 90's), thankfully, but the amount of colors and specific details concerns me a bit.
Also, just going to mention that some of the arm printing isn't possible with Lego's current techniques. I don't think I've ever seen a minifigure with printing that wraps that tightly around the arm.
Also, just going to echo a few opinions from some people I was talking to about this; new molds for Onua would be pretty cool, and that the shield on Onua's chest is a bit odd. This is all personal preference, however.