[RATE MY TEAM] New team for my second Premier Challenge

[Vexian]

So another RMT post. My last Premier Challenge team did ok. I ended up going 2-3 which isn't terrible for my first ever live event. Now for my next challenge I would like do better. I kind of threw this team together with the help of someone in the ReplayFlynn last night and now I am asking for your opinions on what can be done to improve upon this.



Milotic @ Assault Vest
Ability: Competitive
Level: 50
EVs: 252 HP / 84 Def / 168 SpA / 4 SpD
Calm Nature
- Ice Beam
- Icy Wind
- Scald
- Dragon Tail

Offensive Calculations:
168 SpA Milotic Ice Beam vs. 4 HP / 0 SpD Landorus-T: 192-228 (116.3 - 138.1%) -- guaranteed OHKO
168 SpA Milotic Ice Beam vs. 0 HP / 4 SpD Garchomp: 180-216 (98.3 - 118%) -- 93.8% chance to OHKO
168 SpA Milotic Scald vs. 4 HP / 0 SpD Heatran: 102-122 (61 - 73%) -- guaranteed 2HKO after Leftovers recovery
168 SpA Milotic Ice Beam vs. 0 HP / 4 SpD Mega Sceptile: 180-216 (124.1 - 148.9%) -- guaranteed OHKO

Defensive Calculations:
252 SpA Mega Charizard Y Solar Beam vs. 252 HP / 4+ SpD Assault Vest Milotic: 80-96 (39.6 - 47.5%) -- guaranteed 3HKO
252+ SpA  Mega Venusaur Giga Drain vs. 252 HP / 4+ SpD Assault Vest Milotic: 68-84 (33.6 - 41.5%) -- guaranteed 3HKO
252 SpA Zapdos Thunderbolt vs. 252 HP / 4+ SpD Assault Vest Milotic: 78-92 (38.6 - 45.5%) -- guaranteed 3HKO
252 SpA Mega Sceptile Leaf Storm vs. 252 HP / 12+ SpD Assault Vest Milotic: 120-144 (59.4 - 71.2%) -- guaranteed 2HKO



Terrakion @ Lum Berry
Ability: Justified
Level: 50
EVs: 60 HP / 252 Atk / 196 Spe
Jolly Nature
- Rock Slide
- Close Combat
- Protect
- Quick Guard

196 Speed will allow me to outspeed a Jolly Mega Kang before tailwind.



Scizor @ Life Orb
Ability: Technician
Level: 50
EVs: 116 HP / 252 Atk / 140 Spe
Adamant Nature
- Bullet Punch
- Bug Bite
- Knock Off
- Protect



Charizard @ Charizardite Y
Ability: Solar Power
Level: 50
EVs: 180 HP / 252 SpA / 76 Spe
Modest Nature
- Heat Wave
- Solar Beam
- Air Slash/Tailwind
- Protect

For this charizard, I am unsure about running Air Slash for coverage or if I should double up on tailwind incase my Whimsicott is either knocked out or not brought to the battle.



Crobat @ Black Sludge
Ability: Inner Focus
Level: 50
EVs: 124 HP / 252 Atk / 92 SpD / 40 Spe
Adamant Nature
- Brave Bird
- Cross Poison
- U-turn
- Taunt



Whimsicott @ Leftovers
Ability: Prankster
Level: 50
EVs: 252 HP / 108 Def / 148 SpD
Bold Nature
- Beat Up
- Helping Hand
- Tailwind
- Giga Drain

This whimsicott I am completly unsure of. Beat Up for the obvious synergy with Terrakion and Tailwind to speed up the team. I thought of adding Helping Hand to make those +4 Rockslides from terrakion be even more devistating, but if something else better could be added I'd like to know. Also I am not completly sure on its EV spread or Item. Definatly need suggestions in that department.