My Gen 7 OU Singles Team for Showdown

Question

Excalibur (Kartana) @ Life Orb
Ability: Beast Boost
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Leaf Blade
- Sacred Sword
- Night Slash
- Psycho Cut

Igneel (Charizard-Mega-X) @ Charizardite X
Ability: Tough Claws
EVs: 252 Atk / 252 Spe
Jolly Nature
- Thunder Punch
- Flare Blitz
- Brick Break
- Earthquake

Aegis Steelix-Mega @ Steelixite
Ability: Sand Force
EVs: 252 HP / 4 Atk / 52 Def / 200 SpD
Sassy Nature
IVs: 0 Spe
- Dragon Tail
- Stealth Rock
- Toxic
- Gyro Ball

Maria (Blissey) (F) @ Leftovers
Ability: Natural Cure
EVs: 252 HP / 252 Def / 4 SpD
Bold Nature
IVs: 0 Atk
- Aromatherapy
- Toxic
- Soft-Boiled
- Seismic Toss

Zeref (Hoopa-Unbound) @ Life Orb
Ability: Magician
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Gunk Shot
- Nasty Plot
- Hyperspace Hole
- Dark Pulse

Acnologia (Kyurem-Black) @ Icium Z
Ability: Teravolt
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Freeze Shock
- Fusion Bolt
- Dragon Claw
- Stone Edge

Comments

Kartana looks good. Maybe you can run Defog over either of the last two moves

Char-X needs Dragon Dance to devastate opposition. Also Dragon Claw > Brick Break most of the time

Also Eviolite Chansey is used over Blissey, making a change you want to adapt as well?

Hoopa might not be able to set up Nasty Plot, a Spec set will work better imo. Also Gunk Shot is physical so it stays unboosted