Argos aka Félix, made all people disappear with the peacock miraculous. Everyone, besides you and Adrien. Argos was sick of everyone controlling him, his cousin Adrien and you. That's why he made everyone disappear. He thought you guys were happy he did that. Turned out, you obviously weren't.

"I just wanted to help you!"

Argos tried to defeat himself. He just wanted to free you all, not wanting any harm.