Toucannon:
Looks good, the only thing I'd suggest is replacing the Muscle Band with a life orb, Sharp Beak, or Kings Rock (if you have no soul)
Alolan Ninetails:
Again, looks good. You should defiantly replace Ice Beam with Blizzard, Blizzard has 100% accuracy when it is hailing. You also might want to replace Psyshock and/or Calm Mind with Moon Blast and/or Aurora Veil. Moon Blast for your other Same Type Attack Bonus move, Aurora vail (and possibly replace item with light clay) would boost your team's survivability.
Aloan Persian:
You should have the ability Fur Coat instead of technician because the defense boost is much better than making all your 60 power moves 90 power. Your nature should always be minus what ever attack stat you don't use (-Sp.A for Alolan Persian, I recommend Jolly +Speed -Sp. Attack) Alolan Persian's only good stat is speed, so you should use Foul Play instead of Payback. Even if you use an offensive set, replace Shadow Claw, it only hits things that are already covered by your dark STAB. Also remove Return, the only reasons you would use a normal attack is because you are a normal type and get STAB or because the pokemon has a shallow move pool. You should have Parting Shot for pivoting and Taunt instead of Shadow Claw and Return. If you replace Play Rough with something like Toxic or Roar, you should put that attack investment in HP or Defense. You should also have a Darkinuim Z, Z-Parting Shot fully heals what ever pokemon you send in.
Blissey:
Don't bother putting any investment in Blissey's Defense stat. It's so low, it won't make a difference. Use a different nature, Naughty for example. Don't use swagger, gen 7 nerfed confusion so confused pokemon won't hit themselves as often and the last thing a Blissey wants to fight is a pokemon with +2 Attack. Give Blissey some form of HP recovery (Soft Boiled or Wish) I recommend Wish because if you switch, the new pokemon will get the heal (more HP is healed if you have HP investment because Wish heals half of the user's HP to what ever Pokemon is in at the end of the next turn). If you use Wish, you might want to use protect as well, so you can grantee Blissey will get it's own Wish if you are low health. Blissey has a mediocre Sp. Attack stat, so you should replace it's attacks with moves like Protect, Heal Bell, Stealth Rock, or Seismic Toss.
Tsareena:
This one is also good, You should replace Leaf Guard with Queenly Majesty, it blocks priority moves like Fake out and Sucker Punch. Also Replace Attract with a move like U-Turn (for pivoting) Knock Off (to remove items) or Synthesis (to keep your hazard remover healthy, especially because you have High Jump Kick)
Gyarados:
This one really doesn't need very many changes, swap Hasty nature for Jolly nature because you don't use your Special Attack. You might also want to replace a move for Crunch, so you can have Dark STAB after you mega evolve, but that is optional. You already have Dark type attacks covered by your other teammates.
