Rare candies investment

I'd go for a third shadow ball mewtwo, IB isnt really worth considering because weavile is out, and out DPS' IB mewtwo, as well as unreleased Mamoswine and glaceon do as well and with substantially less cost. Shadow ball has a lot of legendary coverage in gen 4, with 3 more legendaries (possibly 4 if origin forme giratina comes out) while IB only covers one, Giratina which shadow ball also covers and deals higher damage against.

If you feel you're good on mewtwo, i'd recommend the kyogre or SA moltres (because when the double move is added for PvP, that sky attack one will also be able to get overheat and given the predictions of PvP, steel will be very prevalent, and for Kyogre, thunder and blizzard offer good counter coverage for PvP, both are also very well suited to raids, Moltres for machamp and kyogre to A-wak and in the rain tyranitar) The kyogre will do well for A-wak raids, having more bulk than shadow ball mewtwo though at the cost of DPS, i'd say since you already have 2 and dont feel you need a third, the kyogre'd be a better option.

What do you have in Rayquaza? Palkia will show up before too long AND Rayquaza makes a superb generalist as well.

SB Mewtwo no doubt about it... I would sit on some rare candy for that moltres till we see how PVP works out at least that’s what I’m doing with my 100 sky attack

Do you regularly do A-Wak raids? Do you want to attempt duoing them? If yes, power up a Kyogre.

Asked above, what's your Rayquaza situation like? Given Palkia's typing it will be the go-to premier counter against it. Cresselia's only around for another week, if we see Palkia after it'll be a pretty urgent need.

With PvP likely a day or so away it may be best to give it another couple of days and see what's good in that front.

Max out a registeel and get a regirock to 2500