How is my team for elite four fight 1?

Giratina: Item=Crystal Shard, Moveset= Dark Matter, New Moon, Hex, Shadow Force. Lvl:90

Huntail: Item= Mystic Water, Moveset= Crunch, Aqua Tail, Surf, Permafrost. lvl: 92

Delta Metagross (spider): Item= None, Moveset= Sticky Web, Gunk Shot, Toxic, Earthquake. lvl: 74 (for now)

Delta Venesaur: Item= Mega Stone(can change), Moveset= Moonblast, Calm Mind, Draining Kiss, Moonlight. lvl: 94

Mew: Item= Shell Bell, Moveset= Transform, Aerial Ace, Ancient Power, Psychic. lvl: 74(for now)

(Soon To Be)Delta Volcarona: Item=?, Moveset=?. lvl: will be 95

Please tell me what to change and tips on how to use those changes against them.

Teach Giratina Calm Mind and Dragon Pulse

ok thanks

anything else?

Keep your team at the same level, because the levels of the elite 4 is the same as the level of your highest level poke.

I would highly suggest getting a pretty good moveset for mew, (you can gave it something like nasty plot+3 attacks? Don’t know about the item). Also, you have a large repeating type. Ordinarily, this would not be an issue, but both of those mons play a similar role and they have somewhat similar coverage. I would suggest replacing one of those psychic types with a fire type. Fire types or fire type moves tend to be pretty solid in the e4 as they love to have a certain mon (scizor).

ok. Should I know anything else?