From the pokemon website
>In the world ofPokémon Sun and Pokémon Moon, you’ll discover moves more powerful than any seen beforeSo it seems like the move in pic related that was shot by greninja from this trailer
https://www.youtube.com/watch?v=aj-34tfTiqois a new move more powerful than any seen before?
Also if it is confirmed a new move, this might be the one to clinch Ash's victory.