a double team with VCG2016 format

this is my team

Dialga Modest Telepathy 252 HP/252 SpeA/4 SpeD
*Shuca berry/Adamant orb
-Flash canon
-Flamethrower
-Trickroom
-Dragon pulse


Landorus-T Jolly 252 Atk/252 Spe/ 4 SpeD
*Muscle Band
-Earthquake
-Uturn
-Rockslide
-Protect

Primal Kyogre Quite 252 HP/252 SpeA/4 Def
-Water Spout
-Origin Pulse
-Protect
-Ice beam

Ferrothron Brave 30/31/30/31/31/1 (252 HP/252 Atk/ 4Def)
*Rocky helmet/Leftover
-Gyroball
-Leechseed
-Protect
-Explosion/HP ice

Mawile Brave 31/31/xx/31/31/x 252 HP/252 Atk/ 4 speD
*Mawilite
-Playrough
-Ironhead
-Protect
-Sucker punch

abd the last, this may make you ask "but why"

Persian Jolly Limber 252 Speed/ 252 SpeD/ 4 HP
*Eject button
-Fake out
-Taunt
-Gunk shot
-Hypnosis/Foul Play

Now lemme explain why
for the Dialga, so obvious
this one has Telepathy and can set up trickroom is the reason why I use it
Flash canon can be use in the turn enemy's Xerneas set up Geomancy, with modest nature and max SpeA IVs, EVs, I can deal tons of damage to the Xerneas even if it had Geomancy set up
Dragon pulse is to hit Gengar, Salamence, Kyogre, TalonFlame, Kangas when I got trickroom set up
Flamethrower is to cover the lack of firetype attack of my team

Landorus-T is to Intimidate Groudon, Salamence and can EQuake the same turn with my Dialga F.Canon the Xerneas

Primal Kyogre is so mainstream right now so I'll not talk much about it except for the Quite nature, best nature for Kyogre to spam Origin Pulse in Trick room

Ferrothron is a little difference from what you usually see
I don't run Power-whip but instead - Explosion
this is the surprise I'll give the enemy when I'm in danger or instead I could run HP ice while Kyogre is in the field if they switch in the Slamence

Mega Mawile - nah, everyone knew this set

And the last one - Persian
while every body out there is overusing Liepard, I, instead, used this classy cat for only one reason
it's SPEED
with the base 115 speed, it can out-speed the enemy's Liepard and make a perfect Fake out OR
Gunk-shot the M*****F***** Xerneas before it uses Geomancy (depend on how lucky I'm to not miss that Gunk-shot)
some ppl run Thunderwave on their Liepard so I run Limber on my cat just for safe
Foulplay is to hit Groudon, Salamence but I don't think I'm gonna run Foulplay since a lot of people run SpeA Groudon recently and f***ed up everything
I also can run Switcheroo to steal the Power herb and give the Xerneas a Choice Band but I'm not sure this will work

Protect is a staple move in doubles formats like VGC for a variety of purposes like stalling out opposing field conditions, giving a partner time to take out a counter, and punishing double targeting.

Speed EVs are pointless on Dialga when you're using Trick Room, since the higher Speed will be used against you. -Speed natures and a low Speed IV should be used because you get to outspeed as much of the normally speeder opposition as possible while Trick Room is up. There's no need for Flamethrower here, since Primal Kyogre's Origin Pulse can hit Steels hard enough. That, and it will become useless while Primordial Sea (whether it's your own or your opponent's) is active:
-Trick Room
-Flash Cannon
-Draco Meteor
-Protect
Nature: Quiet
EVs: 252 HP/100 Def/156 SAtk
Item: Shuca Berry

Muscle Band's minuscule power boost compared to things like Life Orb doesn't make it worth using. Change Landorus' item to Focus Sash or Life Orb.

Ferrothorn's Special Attack is downright pathetic, making Hidden Power a no-go for it. Just stick to Protect.

Liepard is still better than Persian because it has Prankster to give its status moves priority, making Persian's higher Speed not a good reason to be used over Liepard. It also has STAB on Foul Play. Prankster Taunt stops Xerneas from setting up Geomancy, Thunder Wave cripples Xerneas even after it sets up, and Encore is a cruel way to force Xerneas to set up Geomancy again and again while the partner chips away at it. That, and Persian has little to no offensive presence outside of Foul Play, which isn't a STAB move. Remember that under Trick Room, the lowered Speed from paralysis will be used against you:
-Fake Out
-Foul Play
-Encore/Swagger
-Taunt/Fake Tears/Thunder Wave
Nature: Timid
EVs: 252 HP/4 SDef/252 Spe
Item: Focus Sash
Ability: Prankster

yeah, I know but to get a Dialga quite with Telepathy is too hard :( I looked for it but nobody got one
actually I create this team just to fight my friend, not to play rating match :)
but thanks for the advise, I'll remove the muscle-band and HP ice

I'll just add on to what PlatinumDude mentioned.

Draco Meteor > Dragon Pulse:
Draco Meteor, for the most part, has always been the dragon move of choice despite the special attack drop. Dragon Pulse just doesn't have enough power, especially if you're not using Adamant Orb or some other boosting item. Also, Telepathy Dialga can only be modest nature if I'm not mistaken.

Landorus w/ Muscle Band:
Terrible item. Life orb, choice scarf, choice band, or assault vest is what Landorus is known for using. Consider some of these, Landorus is quite versatile when it comes to item choices and has even been known to run special sets in Therian form as well.
Speaking of sets, I'd consider Superpower > u-turn/protect (depending on the item you switch to) because you'd want a way to hit Steel types for super-effective damage in your/opposing rain without having to resort to flamethrower on Dialga.

Ferrothorn:
Yea, HP Ice is garbage on a Pokemon with only base 54 special attack. I noticed you don't have any way to hit opposing Primal Kyogres for supper-effective damage so you might want to opt for Power Whip in the 4th move slot over Explosion/HP Ice.

Persian w/ Eject Button:
Aside from Liepard being better than Persian in every other way but one (faster fake-out, not worth), Eject Button isn't that great on a Pokemon where so much can OHKO it. It's 65/60/65 defenses aren't going to do much for you, so running 252 in attack and speed and switching to Focus Sash are your best options if you don't feel like using Liepard for almost the same role.