Which civilization/faction is this?

The new symbol is very good.

1-Do a brainstorming session on what differentiates the gameplay of each faction. 2-Add a technological cultural tree that includes its entire cosmology and technical development.

There are quite a few representations of Eagles in the religious art of Palmyra. The Eagle of Baalshamin in Palmyra In ancient pre-Islamic Syria, Baalshamin was the god of the sky and the "Lord of the Heavens" in the city of Palmyra. His two main attributes were lightning and the eagle.   At the entrance of his famous temple in Palmyra (which was tragically destroyed by ISIS in 2015), a celebrated stone lintel relief prominently featured an eagle with outstretched wings, symbolizing divine power, sovereignty, and cosmic protection.   https://virtual-museum-syria.org/palmyra/door-lintel-from-the-temple-of-baalshamin/   That's why it was used throughout Rome II.   There is also another symbol of Zenobia riding a Lion. I'll look for it later.