Mega Gyarados! A fan favorite fish! Mega Gyarados is useful for raids, and dominates if allowed in Master league, it can be shiny, so no reason not to try for a big shiny worm fish.
Mega Gyarados loses flying and gains dark, flips from resisting fighting types, to taking super effective, standard Machamp makes an apperance, but that little Kartana sure made a splash on counter charts! I hope you picked up a few, they will be useful!
Go to the official counters page for a complete list including Shadows and Megas to see how your Pokemon perform.