rate my first uber team please :)

#1
As you can probrably tell in the title, i am pretty new to pokemon so i was hoping to get some feedback on my team sorry if my explanations are kind of crap but i'm just beginning to learn most of the stuff xD



Mewtwo @ Leftovers
Trait: Pressure
Shiny: Yes
EVs: 252 Spd / 4 HP / 252 SAtk
Modest Nature
- Psychic
- Shadow Ball
- Aura Sphere
- Calm Mind
basically just running shadow ball to kill those ghosts they use to counter mewtwo, and aura sphere for the darks. Main sp. sweeper of the team.

Lugia @ Leftovers
Trait: Multiscale
Shiny: Yes
EVs: 52 Def / 252 HP / 204 SDef
Bold Nature
- Roost
- Reflect
- Whirlwind
- Ice Beam
Wall of the team, with high survivability as well as decent damage on ice beam against dragons and roost/reflect should be able to allow lugia to survive most encounters.


Arceus @ Silk Scarf
Trait: Multitype
Shiny: Yes
EVs: 252 Atk / 88 HP / 168 Spd
Adamant Nature
- Earthquake
- Shadow Claw
- ExtremeSpeed
- Swords Dance
Main physical sweeper of the team. self explanatory, very common sweeper to run on alot of teams. Shadow claw to counter ghosts who are immune to xtremespeed and speed EVs to boost the speed of the other skills up. I chose silk scarf over choice because in the case they have a ghost up and i have xtremespeed locked in it's pretty annoying.

Kyogre @ Choice Specs
Trait: Drizzle
Shiny: Yes
EVs: 4 Spd / 252 HP / 252 SAtk
Modest Nature
- Scald
- Thunderbolt
- Thunder Wave
- Ice Beam
sp. attacker, not insanely tanky but can take a hit or two. nice versatility on the skillset allows it to deal major damage on alot of matchups. Choice spec's and STABed scald can one shot alot of squishy pokemon.

Tyranitar @ Chople Berry
Trait: Sand Stream
Shiny: Yes
EVs: 76 Atk / 180 HP / 252 SDef
Adamant Nature
- Stone Edge
- Crunch
- Pursuit
- Superpower
Tanky attacker, with Chople berry to counter aura sphere mewtwo, etc. and superpower should be able to take out or at least hurt most pokemon pretty badly

Darkrai @ Leftovers
Trait: Bad Dreams
Shiny: Yes
EVs: 252 SAtk / 252 Spd / 4 SDef
Timid Nature
- Dark Void
- Dark Pulse
- Focus Punch
- Substitute
Open with dark void, if it is able to sleep the enemy pokemon i can then take out arceus and sword dance 1-2x and sweep as many as i can (unless they have counters but thats a different story) Couldnt really think of any other items, so i just put leftovers on him.
 
#2
Your team is very weak to Scarf Terrorkion. ( Terrakion )

Let me complain about every pokemon...

Mewtwo;

Shadow ball is bad in Uber. Replace it with sub. Also invest more into defence & HP ( both sides )

Lugia;

Not as good as Giratina when it's multiscale is broken. Set up fodder.

Arceus;

Replace item with life orb. Helps to secure crucial kills.

Kyogre;

Nothing on your team benefits from the weather. Replace with a Palkia (helps to counter opposing Kyogre)

Tyranitar;

Same with Kyogre, but replace with Scizor (good check to Terrorkion)

Darkrai;

Replace focus punch with focus blast/HP fighting.
 
#3
First, replace psychic with Psystrike on Mewtwo. It is the best move that Mewtwo ever got and basically allows him to mix sweep without compromising IVs.Timid nature should be used over modest. Ice Beam over Shadow Ball is also a very important move on Mewtwo, as it allows him to bypass stuff such as Landorus T and Groudon that can potentially go through Mewtwo. You are very weak to opposing Kyogres, I suggest putting Palkia or Latias in as one of the members in place of Tyranitar, since Tyranitar really does nothing to this team except set up sand, which this team benefits nothing from. Scarf Zekrom despite the fact that it cannot switch into Specs Kyogre works well in revenge killing Kyogres that aren't scarfed. It can also OHKO opposing Arceus if you run Adamant on Zekrom. You also need something that can set up Stealth Rock at least.

Honestly, this team does need a lot of improvements, but once improvements are made, I am sure that you will win a lot of battles to come.