(Uxie is supposed to be used for Dual Screens, and with its bulk, it can do just that.  So it can then whip out either Stealth Rocks or Thunder Wave: if it uses the former and decides to use Thunder Wave, it can then probably switch to Medicham-Mega and use Bulk Up.)

(Alakazam is a direct counter to Muk-Alola, Bisharp, Weavile, Metagross, Dragonite + DDance, or whatever troublesome physical attacker.)

(Xatu's is pretty explanatory, considering there is no Mega Evolution required for it to activate Magic Bounce, allowing it to easily get rid of Hazards and send them over to the opponent's side without much trouble, but what can be a problem is if the opponent predicts you to switch into your Xatu and goes for an attacking move instead of a hazard.  Z-Skill-Swap boosts its speed, but it also swaps abilities.  That, however, can easily be replaced with Rocky Helmet and Skill Swap can be traded for Haze or Wish, to put it more on the clerical side of the battle.  Medicham-Mega, Metagross, and Uxie have no reliable source of healing, but Xatu can help out with that, perhaps.)

(The team is also, mostly, tailored to countering the likes of Chansey and Toxapex, perhaps Ferrothorn as well.  Metagross' Choice Band can be tricked to Chansey or Toxapex, since they are mostly stall, and Metagross possesses an innate immunity to Toxapex's Baneful Bunker anyways.  Malamar can easily Knock Off Chansey's Eviolite and then use Superpower, and if a mon is getting too greedy with high stat changes, then that can be easily changed with Topsy-Turvy, but Malamar's main problem is having to face Volcarona.  As well, Medicham-Mega can easily go for a Bulk Up and then use High Jump Kick on Chansey, so that's good, if it doesn't decide to go for Toxic anyways.  But if the opponent decides to switch out since they don't want to take a High Jump Kick, then the Bulk Up will not go in vain.  And you can also predict Baneful Bunker with Medicham-Mega, too, which means you can go for a Bulk Up and then a Zen Headbutt.  Ice Punch is for Dragons or Grass-types, of course, maybe Gliscor, but Thunder Wave is for threats like Skarmory or Mantine.)