I’ve been thinking about this since I started the series, I really don’t think seawing hybrids should be plausible, wouldn’t the genetics mixing mess up the gills? Based on the dragons anatomy, the gills seem to be a dormant trait that has only been left active in the seawing species , seawing a are likely extremely genetically different from the entirety of the rest of the dragons, they have many features that are not shared with any other species, we see that specialized traits can be lost with cross breeds; Sunny lost the sandwing trademark of the scorpion type tail (which mind you, would be hard to develop as a reptilian, unless they are closer to mammals… in which case the rain wing fangs and bug-like wings of the (idk what they’re called haven’t read far enough but the bee-like and beetle-like dragons))

So In the case of a hybrid seawing, I think realistically the sea wing gills would end up malformed and possibly even be deformed enough to kill the dragonet

Edit: Just leave me alone if you don’t like thinking about things from this type of angle it’s not that hard