Is Zekrom something you want? Yes indeed! You will see it pop up as a top counter in raids for PvE, and you can use that same powered up Zekrom in Masters for PvP. You want as close to perfect as you can find, so raid them up and get some candies!
As for what to use? You can see that dragons rule this raid, some of them can be hard to find, but hopefully you’ve done some community days for garchomp, and don’t forget the swinub incense day December 5th, 11-5pm local time. Don’t leave them sad, bring them home.
Go to the official counters page for a complete list including Shadows and Megas to see how your Pokemon perform.