This is my first Pokemon team that i will make competitive if you have any suggestion or changes for my team,move, natures and hold items that i should use please tell me thanks.

Latios
Evs-4 HP / 252 SpA / 252 Spe
Nature-Timid
ability-levitate
move-set
Dragon Dance
Dragon Pulse
Thunderbolt
psychic

Charizard hold item x stone
Evs-4 Def / 252 SpA / 252 Spe
Nature-Timid
ability-Blaze
move-set
Earthquake
Roost
Dragon claw
Fire blast

Gardevoir-mega evolution stone
Nature-Timid
evs-252 HP / 4 SpD / 252 Spe
ability-Trace
move-set
Reflect
~ Light Screen
~ Memento
~ Taunt / Psychic

Mamoswine-
Evs-252 Atk / 4 Def / 252 Spe
Nature-Thick Fat
abilityJolly
move-set
~ Stealth Rock
~ Endeavor
~ Ice Shard
~ Earthquake

Umbreon
Evs-hp and spd
Nature-
ability-inner forcus
move-set
curse moonlight
toxi curse

need help with final member thanks