It took us until the end of the Sumeru Archon quests to finally see the Sixth Harbinger in action with the release of Scaramouche’s banner on December 2022 with the version 3.3 update.
He made subsequent reappearances in the Inazuma Archon Quest where he served as an antagonist working under the Fatui as the Sixth Harbinger, the Balladeer.
The fact that he’s Anemo does give him a key advantage however and that’s his ability to trigger the Swirl reaction, allowing you to amplify the damage of other elements.