Winged and feathered serpents (they have no official general name that I can find, but they have already been thought up) are nothing like Chinese dragons. While Chinese dragons can be considered "serpentine" because of the elongated body, they are not snake-like by any measure aside from the length and flexibility of their bodies. They tend to have four or more legs, often lack wings, and have a head that is a sort of cross between a lion and a crocodile with antlers. Winged serpents, on the other hand, are snakes with extra features added on, such as up to three pairs of wings (and some cultures have feathered serpents without wings). King Tut had images and statues of winged serpents guarding his tomb, the native american tribes had a number of spirits and dieties in the form of flying feathered serpents (with or without wings), Neopets calls them Hissis, and RPG systems like D&D have winged serpents within their monster manuals.
If you want to call winged serpents spirios, fine, but that's a name suggestion. If you want to invent a creature of your own and call it a spirios, fine, but you should probably have a more in-depth description than "flying snake" or "like a chinese dragon" as both of those have already been invented. You might have been unaware of winged serpent mythology before this, and it is an interesting creature to suggest for this game (not my personal favorite, but still a good idea overall), but it's still not an original concept.
I am curious though, what did you think rocs were, if not thunderbirds? A giant bird with control over lightning by any other name...
