Who’s the sixth?

I like that there’s a royal wedding. It kind of bookends G4 as a whole, since one of the major “event episode” two-parters was A Canterlot Wedding.

Harpy mythology from ancient Greece - as a cultural background for anthro birds that do not have wings. It brings them into the same cultural sphere as the pegasi, and it is possible that the two peoples had a historical relationship in older times. The IDW comic crew has done a lot of good in recent years, the thracians were a very good idea - and although Whitley messed it up with multiple harmony trees, we have a little more about the rest of the world outside of Equestria. Very sad that this had to end, but the G4 will not disappear by itself, this is too big, and IDW has made it bigger.
 
Hope there is more background material in FiM # 100, but the Zebra arc did not deliver much hope in that respect.
 
At least we know that the royals in Ornithia are not hostile to piracy - so there may be actual pirate kings in the history of this country. We know at least that Abyssinia, as a trading power, does not appreciate pirates attacking and looting their airships. And it is possible that the Storm King was at war with Ornithia during his attack on Abyssinia, and that Celaeno may have risen in rank among the pirates by having close friendships with the royal family who may have financed the pirate fleets in the face of the threat. Thus, Celaeno could become a fleet commander for a pirate fleet, as she had contact with many more ships. Celaeno dispersed the fleet to lead them and their prey out of range, but was captured and captured by the Storm King.
 
It is beginning to become clear how “the Storm War” happened in the last years before the final battle of Canterlot, the Storm King and his armada were at war with Abyssinia which was conquered and plundered, while Ornithia may have been the next target. Then he came in contact with Tempest Shadow, who explained to him about the magical kingdom of Equestria. This led to the Storm Armada heading towards the southern part of the continent (with Equestria) where they took control of Klugetown and then eliminated the last threat, Hippogriffia. As soon as the hippogriffs were cleared of the road, the next stop was Canterlot. For Ornithia, it may have been a stroke of luck that the Storm King met Tempest, because it is possible that they would have lost in the end against the well-disciplined armada.
 
Instead, it disintegrated after the death of the Storm King and his second-in-command, Tempest, defected, revealing all about the military apparatus and the conquests to the authorities in Equestria and the other kingdoms. It is possible that it was her confession that triggered the important conference in Mount Metazoa, as it became possible to clear away the empire that had been created by the Storm King. Ornithia played a very important role in this by sending out pirates to fight the Storm King. Then we can understand why Twilight was in Mount Metazoa - she was an important witness during the conference, as she took the defector under her protection.
 
The fans can now create alternative universes of airship warfare with Equestria, Abyssinia, Ornithia and the Storm empire - and it is possible that the Farasi kingdoms (there are four princes there) can also be included, but they are possibly on a third continent. The diamond dogs, hard to say - but their decentralized kingdom means that it is not unthinkable.
 
In our world, it is inconceivable for many centuries that royals would associate with real pirates. Even when Queen Elizabeth supported and hired pirates in the 16th century, it was by using rhetoric and social rules that hid this truth. By saying it openly without his father protesting against this - the prince has revealed how the royal power treated pirates in Ornithia.

Oh and Thaumas and Ozomeme are the parents of the Harpies.

Aeollo and Ocypete? Guess they are contiunuing the Harpy naming theme starte with Celaeno. In Greek Mythology Zephyrus is also the mate of the Harpy Podarge.