Buffs:
Lupina
Ability: Sheer Force , Moxie , Infiltrator
Base stats: 70 (-10), 110, 65 (-10), 85 (swapped with SpD), 70 (-10), 130 (+30)
New moves
Gunk Shot, Parting Shot
Instead of trying to make it an AoA wallbreaker like it was before, it's now more of an offensive pivot. Hit fast, hit hard, and if you come across something you can't break, Parting Shot out. You could even use Z-Parting Shot to restore a teammate's HP. Sheer Force gives it a lot of power, so it could also clean late game. It can also put in work vs Fairy teams, as it ties with Tapu Koko and can do massive damage to a Fairy team with its Sheer Force boosted Gunk Shot.
Temprasect
Ability: Dancer, Tinted Lens
Base stats: 50, 120, 60, 90 (swapped with Spe), 70, 110
New moves
Close Combat, Dragon Hammer, Poison Jab, Sticky Web
While it was a mediocre mixed attacker, this new take on Temprasect trades its ability to go Special for a much better Speed tier and a much better ability. Thanks to Tinted Lens, its STAB combination is now almost unresisted, with only a handful of Fairy types able to switch in. On Bug teams I suspect it will run a Choice Band set, as they already have Galvantula and Araquanid to set webs. It now also gives Dragon teams a Sticky Web setter, meaning Mega Altaria and Kommo-O can outrun Scarf Greninja after 1 boost.
Nerfs:
Flooduel
Ability: Torrent, No Guard
Base stats: 55, 102 (+10), 101, 121 (+10), 80 (+10), 81 (-30)
New moves: Dynamic Punch
Lost moves: Nasty Plot
By reducing Flooduel's Speed and taking away Nasty Plot, it goes from being a nigh unstoppable sweeper to an almost impossible to switch into wallbreaker. To compensate for the much lower Speed, it has better Attack and slightly better defences. I think it will be more balanced now, as even though it hits even harder its average Speed means it's easily forced out by faster Pokemon.
New mechanic: Ice types gain 50% defence in Hail. It gives the Ice type some much needed extra viability, it makes Ninetales-Alola less fragile, and it makes Sandslash-Alola harder to revenge kill with (non SE) priority.