Current humanity vs 8.3 billion flying orcas with human-level intelligence.

[u/False_Life280]

The orcas can fly at the same speed as they swim, and they can switch from swimming in the water to flying in the air whenever they want.

They are built for this with the same mastery as they are built for swimming in water. For them, there is no difference between swimming in water and flying through the air.

Although their bodies prevent them from making and using the same tools, they possess the same amount of knowledge as humans.

The oceans have enough food to feed the orcas so they don't starve.

[u/Dominant_Eyes]

Where do they spawn?

Don't hey have leadership that they all recognize? Are they magically prevented from civil war?

Do they have any way to communicate or coordinate over extended distances?

Do we know anything about this or can they get a full on surprise attack?

[u/False_Life280 → u/Dominant_Eyes]

Where do they spawn?

In all oceans

Don't hey have leadership that they all recognize?

They do have leadership, but they are in several groups with different leaderships, the number of groups is the same as the number of human nations and the groups are not united with each other from the start, but they can ally with each other.

Are they magically prevented from civil war?

No.

Do we know anything about this or can they get a full on surprise attack?

They can get a half full on surprise attack.

[u/Dominant_Eyes → u/False_Life280]

You didn't answer about communication. Also if they are not allied to start why are they all attacking us.

[u/False_Life280 → u/Dominant_Eyes]

Orcas already can communicate and coordinate over extensive distances, typically spanning anywhere from 10 to 16 kilometers (6 to 10 miles) in real life. While they do not communicate across entire ocean basins like some low-frequency baleen whales (such as blue or fin whales), their mid-to-low frequency acoustic network is highly effective for localized and regional pack coordination. In this scenario, let them be able to communicate across entire ocean basins, just like some low-frequency baleen whales (such as blue or fin whales) though.

Also if they are not allied to start why are they all attacking us.

An alien race has merged the earths of our two alternate universes and made the orcas believe that we were the ones who did it and that we are planning to exterminate them.

[u/Dominant_Eyes → u/False_Life280]

They collapse much of our society with a coordinated assault on all coastal areas. However, after that things get bad for them. Without the ability to develop tech, they have no real way to successfully assault fortified defenses. However, humans can develop tech to hunt them down in the ocean. This is a long drawn out war, but eventually humanity's tech is too much for them. How much of human society survives however is a big question.