Mewtwo...91%...11Atk
Ok, i know how Ex-raid system is hated here but i’ll ask because i’m really wondering what to do with this. On the second ex wave I caught a 76% 11atk Mewtwo, which I maxed out 1 month and a half later because well, it’s always Mewtwo and I didn’t think I could get another after 6 failed new waves. Today I caught this. I’m sitting on 390 rare candies and 1,6 mln dust, so these resources are not a problem. But is it worth it?? I didn’t get the 31th pass but i think Mewtwo is a beast even at 66%. What would you guys do?

Answers
For all of you with low attack Mewtwos.
If you're not confident that your town gets a ton of EX-Raids and that you'll be invited to these, max out your Mewtwo. Don't just take it to level 30 because that won't help you much. You can just evolve a weather-boosted Abra for better results.
If you get a better Mewtwo, then consider having the weaker one be Confusion/Focus Blast. If not, keep the lower attack one as Confusion/Shadow Ball. Mewtwo is glassy enough that Mewtwos in number are useful, and Confusion is a slow enough move that Attack IVs won't make as big of a difference. Multiple Mewtwos make raids much easier. If you DO get a better Mewtwo, I would max it eventually but hold off on it for now, for there are some really good legendaries out right now that make great generalists as well as really good specialists.
Thank you all, i think i'll drop a hundred candies on him and wait the next week to see if i get another pass. 91% IV Is great on Mewtwo, but i'm really full of Psychic attackers so i was considering TM one to Focus Blast. Which one?? The one i already maxed (C\ShB) or the new one (PC\ShB)?? I would go for it immediately, but i always keep myself over 1,2 mln dust and i'm considering max out at least a Kyogre and take the 96% to lvl 30. That's why i'm holding off for now. Also new Pokemons will come in three weeks or so, assuming this time they'll finally release Salamence, which is my favourite Dragon-Type mon. Thanks for your answers, i really needed some advices.
I mean they're both the same Attack IV right? If you have the TMs to spare I guess the 91% would be better to have Shadow Ball since it could use the added bulk to fire off more Shadow Balls before fainting. Bulk isn't a huge factor for the Focus Blast Mewtwo since it'll primarily see use in gym sweeping and min/maxing isn't as big of a factor in that regard.
Really though if the Shadow Ball Mewtwo is already powered up and you don't plan on powering up another one soon I would keep your powered Mewtwo with Shadow Ball for now since it's much more useful.