Please help with Battle Maison team

[drago0202]

Hi everyone. I'm nearly done with the main part of Omega Ruby and plan on beating the battle maison. In X my best win streak for super singles was 35, but I hope to beat it this time around. I have an idea for my singles team:
Gengar (lead/ special sweeper)
Nature: Timid
Ev: 252 spatk/ 252 speed/ 4 Hp
Item: Life orb
moves:
-Sludge bomb
-shadow ball
-focus blast
-substitute
Sylveon ( cleric/tank set) ( pixilate ability)
Nature: Bold
Ev: 252 Hp/ 220 Def/ 36 spdef
item: leftovers
moves:
- hyper voice
- Wish
- Heal Bell
- protect
Mega Charizard X ( physical sweeper)
Nature: Adamant
Ev: 252 atk/252 speed/ 4 spdef
item: Charizardite X
Movies:
flare blitz
dragon dance
dragon claw
earthquake

Please let me know what you think of my ideas. I'm hoping to use a team that either includes latios or mega charizard X
Thank you!