[RATE MY TEAM] Rate my SM VGC17 Team!

[Outsanity1132]

Hi, can you guys in this community rate my team and help me make some changes I need to make in this team? Thanks if you do!
This is my team-

Kartana @Assault Vest
Jolly Nature
Ability: Beast Boost
252Atk-252Spe-4SpD
Leaf Blade
Smart Strike
Sacred Sword
Night Slash

Nihilego @Focus Sash
Timid Nature
Ability: Beast Boost
252SpA-252Spe-4HP
Power Gem
Protect
Thunderbolt
Sludge Bomb

Garchomp @Choice Scarf
Jolly Nature
Ability: Rough Skin
252Atk-252Spe-4Def
Earthquake
Stone Edge
Iron Head
Outrage

Porygon2 @Eviolite
Calm Nature
Ability: Download
244HP-188SpD-76Def
Tri Attack
Ice Beam
Toxic
Protect

Ninetales-Alola @Light Clay
Timid Nature
Ability: Snow Warning
252SpA-252Spe-4SpD
Blizzard
Moonblast
Freeze-Dry
Aurora Veil

Tapu Koko @Choice Specs
Timid Nature
Ability: Electric Surge
252SpA-252Spe-4SpD
Thunderbolt
Dazzling Gleam
Volt Switch
(idk what move to put here)