It is the year, 2045. It is new era of Teyvat, it changed since the Titans' existence was exposed to the public. Alien Kaiju came from The Breach and starts to attack the cities but The Jaeger Program, created by MONARCH Team created the mechs to repel the Kaiju. All cities in Teyvat have been modernized with such technologies, futuristic vehicles, and multiple skyscrapers.

Mondstadt.

Liyue.

Inazuma.

And other cities in Teyvat, All people from around the world, identified Earth Titans as Teyvat's Guardians led by the King of the Monsters, Godzilla. MONARCH observed them study their behaviors with their new technology, ORCA. An echolocation for the Titans to communicate with Titans, knowing that it can speak. But they lived in fear of the Kaiju who came from the breach. But with PPDC they can able to repel the Kaiju from destruction using Mechs called Jaegers. They created the successor of Gipsy Danger, called Gipsy Avenger.

A more advanced Jaeger Mech for all of the best pilots, then they created the new generations of the Jaegers:

Saber Athena

Guardian Bravo

Bracer Phoenix

And other Jaegers who were more advanced than others. It does change everything. Meanwhile, in the Shatterdome. Kazuha and Gorou were recruited into the Jaeger Program they will pilot the Gipsy Avenger. Followed by Neill, Venti, Makoto, Xiao, Cyno, and Nilou.

Kazuha: This is it, Gorou, we're going out to fight the Kaiju.
Gorou: Yeah, I hope that Aether and his family will be moving here.
Venti: I agree with that. Neill and I also enlisted here.
Neill: To protect our people.
Cyno: Sure.

Then they will fight against the Kaiju. First, they must train.