This move is only available to Eternal Floette, an event Pokémon that has never been made available. Despite this, the move (as well as its user) were both programmed into USUM with both a new animation and an entirely new dex entry. When SwSh was datamined, it was discovered that several legacy moves were wiped altogether, like the oft-used Pursuit and Hidden Power. You know what wasn't wiped? Light of Ruin. It even got a brand-new animation. Again. The Flabébé line was wiped in its entirety, and all of us know Eternal Floette has long been relegated to the dustbin of history, but instead of keeping MOVES THAT ARE ACTUALLY USED, they kept this shit. Again. What the fucking hell?