When he finally met his sister she refused to leave and looked at him coldly...

Aether could not restrain himself and became very angry and disappointed at everyone.

"Did I deserve this?..."

His body glowed and he activated his light power. The guy rose into the sky, smiled evilly and began to accumulate a huge ball of light that would fall on Teyvat

You worked for Celestia and as soon as Celestia noticed what Aether was up to, she sent you to stop him