Xurkitree, lightning in a tube man! It’s going to be quite a useful lightning attacker, so you will want one for that, and XL farming while you wait for a shiny to be released. I’m not sure it will get much use on the PvP side, but make sure to pick them up anyway!
Nothing but ground here, the megas are just pure dps, but ground is all you want for your regular counters. Ryperior comes in pretty handy, since you don’t need a special move to make it work.
Go to the official counters page for a complete list including Shadows and Megas to see how your Pokemon perform.