This is my first RMT. I wanted to see if a weatherless team can be any good and I've been having decent success on PO with it. I have 1446 points there. I don't play on Showdown very much because my internet is pretty slow and Showdown tends to lag.

Dialga @ Leftovers Trait: Pressure
EVs: 240 HP / 252 SAtk / 16 Spd
Modest Nature (+SAtk, -Atk)
- Dragon Pulse
- Flamethrower
- Stealth Rock
- Thunder Wave
I picked Dialga because I needed someone reasonably bulky that could set up rocks while also having some offensive presence. Flamethrower is for Ferrothorn and Forretress. I'm running T-Wave on Dialga to cripple Kyogre leads and anything that switches in on him. His EV spread is pretty simple. I decided to run 16 speed EVs to make sure he was faster than base 90s with 4 or 8 EVs put into speed. I also maxed his special attack so he would hit harder. The rest of the EVs got put into HP to make him have more bulk. Dialga is usually my Pokemon that faints first but he can usually set up rocks and paralyze someone.

Arceus-Dark @ Dread Plate
Trait: Multitype
EVs: 252 HP / 4 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Calm Mind
- Judgment
- Recover
- Refresh
I used to have a Palkia here but I needed something that could check CM Arceus Ghost because if he got set up he'd rip through my entire team. I tried using Darkrai but I didn't think he had good synergy with my team. I settled on Arceus Dark because he does a better job than Darkrai. I run max HP so he has more bulk which makes it easier for him to set up. It also helps him tank unboosted physical hits. I use max Speed so he can speed tie with other Arceus forms. When this guy gets a few Calm Mind boosts he's really hard to stop. I think Arceus Dark is a really underused wall breaker.

Mewtwo @ Leftovers
Trait: Pressure
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Aura Sphere
- Ice Beam
- Psystrike
- Taunt
This is Mewtwo set I made. I picked Taunt because I was having problems with Lugia and since most of them only run Ice Beam or no attack moves at all Mewtwo shuts him down. Taunt also helps against Forretress, Ferrothorn, Chansey, Blissey, and Darkrai. I picked the three attacking moves i felt would give Mewtwo the best coverage. The EVs are simple. Max speed so I can outspeed Darkrai. I put the rest in Special Attack so he could do more damage. Mewtwo is probably my main stall breaker because of Taunt. No one really expects him to have it and it often catches my opponent by surprise.

Blaziken (M) @ Chilan Berry
Trait: Speed Boost
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Hi Jump Kick
- Protect
- Shadow Claw
- Swords Dance
Even though I decided to not use weather I wanted to use Blaziken because I think he's cool and doesn't get used enough. I decided to not run Flare Blitz because I don't have sun and if the enemy has rain it wouldn't be very good. I used Shadow Claw instead because it hits Giratina and Lugia harder than HJK does. I picked Chilan berry because one of the most common things that switches in to revenge kill Blaziken is Extremekiller. This guarantees that Blaziken takes a maximum of 46% from an Extremespeed and he can usually OHKO Arceus with HJK if Arceus takes hazard damage.

Latios (M) @ Soul Dew
Trait: Levitate
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Dragon Pulse
- Grass Knot
- Hidden Power [Fire]
- Psyshock
I picked Latios because it can easily kill all of the weather users. Grass Knot OHKOs the standard Groudon and does over 85% to a standard Kyogre. It also 2HKOs Tyranitar. Psyshock is for Chansey, Blissey, and Ho-oh. Hp Fire is for Ferrothorn and Forretress. The EVs for this set are simple. Max speed so it can outspeed anything below base 110 speed that doesn't have a scarf. This guy is usually my MVP. If I predict well enough with him he usually takes out half of my opponents team.

Skarmory (M) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 252 SDef / 4 Spd
Bold Nature (+Def, -Atk)
- Roost
- Spikes
- Toxic
- Whirlwind
I realized that I had nothing that could phaze reliably because I had a Giratina in this spot originally. I also had nothing that could try and tank a Draco Meteor and heal off the damage. I picked Skarmory because it has reliable healing, access to spikes, and it does a good job and checking Extremekillers. There's not really much more to say about Skarmory other than it's here to tank a few hits and lay down spikes.
The only things I really have a hard time against are any sand team that manages to set up their Excadrill because without weather he's really hard to stop. I also have trouble with rain teams that run a Swords Dance Kabutops because he OHKOs or 2HKOs my entire team. I really can't do anything about these Pokemon unless I run a Rayquaza but I don't know if I could make one fit into my team. This team also has a massive weakness to Heatran but he doesn't seem to be very common and I can usually beat him if I predict well enough.
Any ways I could improve this team without using weather would really be appreciated. Thanks for reading this guys.