Needing help

[Sonata]

I like my team overall I just can't decide which of the steel types I have are the better choice. Open to really any suggestions.

Ninjask @ Leftovers
Ability: Speed Boost
EVs: 252 HP / 4 SDef / 252 Def
Impish Nature
- Baton Pass
- Swords Dance
- Protect
- Substitute

Blissey (F) @ Leftovers
Ability: Serene Grace
EVs: 252 SAtk / 252 HP / 4 SDef
Modest Nature
- Blizzard
- Fire Blast
- Thunder
- Grass Knot

Conkeldurr @ Leftovers
Ability: Iron Fist
EVs: 252 Atk / 252 HP / 4 SDef
Adamant Nature
- Drain Punch
- Ice Punch
- Smack Down
- Knock Off

Tyranitar @ Tyranitarite
Ability: Sand Stream
EVs: 252 Atk / 252 HP / 4 SDef
Adamant Nature
- Crunch
- Earthquake
- Superpower
- Stone Edge

Azumarill @ Assault Vest
Ability: Huge Power
EVs: 252 Atk / 252 HP / 4 SDef
Adamant Nature
- Play Rough
- Brick Break
- Aqua Tail
- Ice Punch

Replaceable:

Heatran @ Air Balloon
Ability: Flash Fire
EVs: 252 SAtk / 252 HP / 4 SDef
Modest Nature
- Eruption
- Dragon Pulse
- Dark Pulse
- Earth Power

Aggron @ Aggronite
Ability: Sturdy
EVs: 252 Def / 76 HP / 180 Atk
Impish Nature
- Avalanche
- Metal Burst
- Counter
- Magnet Rise

Scizor @ Scizorite
Ability: Technician
EVs: 252 Atk / 252 HP / 4 SDef
Adamant Nature
- Aerial Ace
- Bug Bite
- Bullet Punch
- Pursuit

Metagross @ Occa Berry
Ability: Clear Body
EVs: 252 Atk / 252 HP / 4 SDef
Adamant Nature
- Zen Headbutt
- Earthquake
- Rock Slide
- Meteor Mash

 

[PlatinumDude]

Ninjask is outclassed by Scolipede because the latter has better offensive presence. Its Stealth Rock weakness also isn't as crippling:
-Megahorn
-Spikes/Toxic Spikes
-Swords Dance/Toxic Spikes
-Baton Pass/Earthquake/Rock Slide
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Focus Sash
Ability: Speed Boost

or
-Swords Dance/Iron Defense
-Protect/Megahorn
-Substitute/Megahorn
-Baton Pass
Nature: Timid/Jolly
EVs: 248 HP/208 SDef/52 Spe
Item: Mental Herb/Black Sludge
Ability: Speed Boost

Blissey is terrible for an offensive role because its Special Attack isn't high enough to make the most of its wide movepool. It's better left to support roles on the team:
-Aromatherapy/Heal Bell
-Soft-Boiled
-Seismic Toss/Flamethrower
-Toxic/Thunder Wave
Nature: Bold
EVs: 4 HP/252 Def/252 SDef
Item: Leftovers
Ability: Natural Cure

As I told you in your profile, Smack Down is a terrible option for Conkeldurr. It's weak and Flying Pokemon hate Ice Punch and Stone Edge even more; the latter is even twice as strong as Smack Down. Assault Vest or Bulk Up are the best ways to use it:
-Drain Punch
-Mach Punch
-Knock Off
-Ice Punch/Stone Edge
Nature: Adamant
EVs: 188 HP/252 Atk/48 SDef/20 Spe
Item: Assault Vest
Ability: Guts

or
-Bulk Up
-Drain Punch
-Mach Punch
-Knock Off/Stone Edge/Ice Punch
Nature: Adamant
EVs: 252 Atk/4 Def/252 SDef
Item: Leftovers
Ability: Guts

Take note that Mega Tyranitar has enough Speed to use Dragon Dance effectively, so you might as well do that:
-Dragon Dance
-Stone Edge/Crunch
-Ice Punch/Crunch
-Earthquake
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Tyranitarite
Ability: Sand Stream

Without Dragon Dance, Mega Tyranitar is slow. If you don't want to use Dragon Dance on it, you might as well make do with regular Tyranitar:
-Stone Edge
-Crunch
-Pursuit
-Earthquake/Ice Punch
Nature: Jolly/Adamant
EVs: 252 Atk/4 Def/252 Spe (Jolly) or 180 HP/252 Atk/76 Spe (Adamant)
Item: Choice Scarf (Jolly)/Choice Band (Adamant)
Ability: Sand Stream

or
-Crunch
-Stone Edge/Ice Beam
-Earthquake
-Stealth Rock/Fire Blast
Nature: Impish/Relaxed
EVs: 248 HP/252 Def/8 SDef
Item: Leftovers
Ability: Sand Stream

For Assault Vest Azumarill, Power-Up Punch is the superior option over Brick Break, as AV Azumarill isn't as strong as the Choice Band and Belly Drum variants. Play Rough already handles Dragon Pokemon, while Waterfall and Aqua Jet already cover Gliscor and Landorus, so there's no reason to use Ice Punch. Azumarill also likes its priority Aqua Jet:
-Aqua Jet
-Play Rough
-Power-Up Punch
-Waterfall/Knock Off
Nature: Adamant
EVs: 16 HP/252 Atk/240 SDef
Item: Assault Vest
Ability: Huge Power

Here's Choice Band and BellyJet Azumarill if you're interested:
-Waterfall
-Aqua Jet
-Play Rough
-Superpower/Knock Off
Nature: Adamant
EVs: 164 HP/252 Atk/92 Spe
Item: Choice Band
Ability: Huge Power

or
-Belly Drum
-Aqua Jet
-Play Rough
-Waterfall/Superpower
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Sitrus Berry
Ability: Huge Power


And as for your replacements:

Eruption Heatran can only have a Quiet nature, as the Pokemon Ranger event set it that way. Outside of Trick Room teams, Eruption Heatran is worthless:
-Lava Plume
-Protect
-Taunt/Roar/Stealth Rock
-Toxic/Will-o-Wisp
Nature: Calm
EVs: 248 HP/8 Def/252 SDef
Item: Leftovers
Ability: Flash Fire

or
-Fire Blast/Overheat
-Flash Cannon
-Earth Power/Stone Edge (latter Choice Scarf only)
-Flamethrower/Fire Blast/Hidden Power (Ice)
Nature: Modest
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Specs/Choice Scarf
Ability: Flash Fire

While Mega Aggron is bulky enough for Metal Burst and Counter, it's not worth it because both moves rely on Aggron being attacked. Once your opponent sees what this Aggron is up to, they'll use it as setup bait:
-Stealth Rock
-Heavy Slam/Iron Head
-Thunder Wave/Ice Punch
-Earthquake/Rock Slide
Nature: Relaxed
EVs: 252 HP/16 Def/240 SDef
Item: Aggronite
Ability: Sturdy

or
-Rest
-Sleep Talk
-Heavy Slam/Iron Head
-Earthquake/Ice Punch
Nature: Relaxed
EVs: 252 HP/16 Def/240 SDef
Item: Aggronite
Ability: Sturdy

Though Scizor's Aerial Ace benefits from the Technician boost, it doesn't see much use besides hitting the occasional Breloom and Chesnaught super effectively. Flying spam is better left to Talonflame and Mega Pinsir (and to a lesser extent, Staraptor):
-Swords Dance
-Bullet Punch
-U-turn/Bug Bite/X-Scissor/Knock Off
-Roost
Nature: Adamant
EVs: 248 HP/136 Def/104 SDef/20 Spe
Item: Scizorite
Ability: Technician

or
-Swords Dance
-Bullet Punch
-U-turn/Bug Bite
-Knock Off/Superpower
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Scizorite
Ability: Technician

or
-U-turn
-Bullet Punch
-Superpower
-Pursuit/Knock Off
Nature: Adamant
EVs: 248 HP/252 Atk/8 SDef
Item: Choice Band
Ability: Technican

or
-U-turn
-Bullet Punch/Knock Off
-Defog
-Roost
Nature: Impish
EVs: 248 HP/252 Def/8 SDef
Item: Scizorite
Ability: Technician

Metagross has fallen out of favor because it never changed throughout the generations, while the metagame around it has. Not only that, but its best move, Meteor Mash, got nerfed and Metagross is now weak to Ghost and Dark. So I wouldn't really bother with it. But if you insist on using it, here's the best it can do:
-Meteor Mash
-Zen Headbutt
-Earthquake
-Pursuit
Nature: Adamant
EVs: 252 HP/252 Atk/4 SDef
Item: Assault Vest
Ability: Clear Body

or
-Stealth Rock
-Meteor Mash
-Earthquake
-Zen Headbutt/Pursuit/Trick
Nature: Adamant
EVs: 252 HP/252 Atk/4 SDef
Item: Leftovers/Iron Ball
Ability: Clear Body

 

[Sonata]

Ninjask is outclassed by Scolipede because the latter has better offensive presence. Its Stealth Rock weakness also isn't as crippling:
-Megahorn
-Spikes/Toxic Spikes
-Swords Dance/Toxic Spikes
-Baton Pass/Earthquake/Rock Slide
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Focus Sash
Ability: Speed Boost

or
-Swords Dance/Iron Defense
-Protect/Megahorn
-Substitute/Megahorn
-Baton Pass
Nature: Timid/Jolly
EVs: 248 HP/208 SDef/52 Spe
Item: Mental Herb/Black Sludge
Ability: Speed Boost

Blissey is terrible for an offensive role because its Special Attack isn't high enough to make the most of its wide movepool. It's better left to support roles on the team:
-Aromatherapy/Heal Bell
-Soft-Boiled
-Seismic Toss/Flamethrower
-Toxic/Thunder Wave
Nature: Bold
EVs: 4 HP/252 Def/252 SDef
Item: Leftovers
Ability: Natural Cure

As I told you in your profile, Smack Down is a terrible option for Conkeldurr. It's weak and Flying Pokemon hate Ice Punch and Stone Edge even more; the latter is even twice as strong as Smack Down. Assault Vest or Bulk Up are the best ways to use it:
-Drain Punch
-Mach Punch
-Knock Off
-Ice Punch/Stone Edge
Nature: Adamant
EVs: 188 HP/252 Atk/48 SDef/20 Spe
Item: Assault Vest
Ability: Guts

or
-Bulk Up
-Drain Punch
-Mach Punch
-Knock Off/Stone Edge/Ice Punch
Nature: Adamant
EVs: 252 Atk/4 Def/252 SDef
Item: Leftovers
Ability: Guts

Take note that Mega Tyranitar has enough Speed to use Dragon Dance effectively, so you might as well do that:
-Dragon Dance
-Stone Edge/Crunch
-Ice Punch/Crunch
-Earthquake
Nature: Jolly
EVs: 252 Atk/4 Def/252 Spe
Item: Tyranitarite
Ability: Sand Stream

Without Dragon Dance, Mega Tyranitar is slow. If you don't want to use Dragon Dance on it, you might as well make do with regular Tyranitar:
-Stone Edge
-Crunch
-Pursuit
-Earthquake/Ice Punch
Nature: Jolly/Adamant
EVs: 252 Atk/4 Def/252 Spe (Jolly) or 180 HP/252 Atk/76 Spe (Adamant)
Item: Choice Scarf (Jolly)/Choice Band (Adamant)
Ability: Sand Stream

or
-Crunch
-Stone Edge/Ice Beam
-Earthquake
-Stealth Rock/Fire Blast
Nature: Impish/Relaxed
EVs: 248 HP/252 Def/8 SDef
Item: Leftovers
Ability: Sand Stream

For Assault Vest Azumarill, Power-Up Punch is the superior option over Brick Break, as AV Azumarill isn't as strong as the Choice Band and Belly Drum variants. Play Rough already handles Dragon Pokemon, while Waterfall and Aqua Jet already cover Gliscor and Landorus, so there's no reason to use Ice Punch. Azumarill also likes its priority Aqua Jet:
-Aqua Jet
-Play Rough
-Power-Up Punch
-Waterfall/Knock Off
Nature: Adamant
EVs: 16 HP/252 Atk/240 SDef
Item: Assault Vest
Ability: Huge Power

Here's Choice Band and BellyJet Azumarill if you're interested:
-Waterfall
-Aqua Jet
-Play Rough
-Superpower/Knock Off
Nature: Adamant
EVs: 164 HP/252 Atk/92 Spe
Item: Choice Band
Ability: Huge Power

or
-Belly Drum
-Aqua Jet
-Play Rough
-Waterfall/Superpower
Nature: Jolly
EVs: 4 HP/252 Atk/252 Spe
Item: Sitrus Berry
Ability: Huge Power


And as for your replacements:

Eruption Heatran can only have a Quiet nature, as the Pokemon Ranger event set it that way. Outside of Trick Room teams, Eruption Heatran is worthless:
-Lava Plume
-Protect
-Taunt/Roar/Stealth Rock
-Toxic/Will-o-Wisp
Nature: Calm
EVs: 248 HP/8 Def/252 SDef
Item: Leftovers
Ability: Flash Fire

or
-Fire Blast/Overheat
-Flash Cannon
-Earth Power/Stone Edge (latter Choice Scarf only)
-Flamethrower/Fire Blast/Hidden Power (Ice)
Nature: Modest
EVs: 252 SAtk/4 SDef/252 Spe
Item: Choice Specs/Choice Scarf
Ability: Flash Fire

While Mega Aggron is bulky enough for Metal Burst and Counter, it's not worth it because both moves rely on Aggron being attacked. Once your opponent sees what this Aggron is up to, they'll use it as setup bait:
-Stealth Rock
-Heavy Slam/Iron Head
-Thunder Wave/Ice Punch
-Earthquake/Rock Slide
Nature: Relaxed
EVs: 252 HP/16 Def/240 SDef
Item: Aggronite
Ability: Sturdy

or
-Rest
-Sleep Talk
-Heavy Slam/Iron Head
-Earthquake/Ice Punch
Nature: Relaxed
EVs: 252 HP/16 Def/240 SDef
Item: Aggronite
Ability: Sturdy

Though Scizor's Aerial Ace benefits from the Technician boost, it doesn't see much use besides hitting the occasional Breloom and Chesnaught super effectively. Flying spam is better left to Talonflame and Mega Pinsir (and to a lesser extent, Staraptor):
-Swords Dance
-Bullet Punch
-U-turn/Bug Bite/X-Scissor/Knock Off
-Roost
Nature: Adamant
EVs: 248 HP/136 Def/104 SDef/20 Spe
Item: Scizorite
Ability: Technician

or
-Swords Dance
-Bullet Punch
-U-turn/Bug Bite
-Knock Off/Superpower
Nature: Adamant
EVs: 252 Atk/4 SDef/252 Spe
Item: Scizorite
Ability: Technician

or
-U-turn
-Bullet Punch
-Superpower
-Pursuit/Knock Off
Nature: Adamant
EVs: 248 HP/252 Atk/8 SDef
Item: Choice Band
Ability: Technican

or
-U-turn
-Bullet Punch/Knock Off
-Defog
-Roost
Nature: Impish
EVs: 248 HP/252 Def/8 SDef
Item: Scizorite
Ability: Technician

Metagross has fallen out of favor because it never changed throughout the generations, while the metagame around it has. Not only that, but its best move, Meteor Mash, got nerfed and Metagross is now weak to Ghost and Dark. So I wouldn't really bother with it. But if you insist on using it, here's the best it can do:
-Meteor Mash
-Zen Headbutt
-Earthquake
-Pursuit
Nature: Adamant
EVs: 252 HP/252 Atk/4 SDef
Item: Assault Vest
Ability: Clear Body

or
-Stealth Rock
-Meteor Mash
-Earthquake
-Zen Headbutt/Pursuit/Trick
Nature: Adamant
EVs: 252 HP/252 Atk/4 SDef
Item: Leftovers/Iron Ball
Ability: Clear Body

I will heed your advice on Ninjask, Azumarill, and I will use D Dance Tyranitar. It's my first time using Azumarill so I don't know much about it, however I will continue to say I prefer Smack Down on Conkeldurr solely for the reason of pokemon with levitate that would otherwise take 3-4 turns to KO over 2 turns depending on the flow of battle up to that point. I'll switch out Scizor's Pursuit for Roost since Pursuit was just a placeholder in my mind for the sake of having 4 moves. Blissey is one of my best in battle because even with it's mediocre SpA it still 2 hits most pokemon, covers a lot of types, and with Serene Grace there's a greater chance of the moves' statuses being inflicted which can change the tide of battle greatly, however I do need to switch Grass Knot with Psychic.

 

[PlatinumDude]

I will heed your advice on Ninjask, Azumarill, and I will use D Dance Tyranitar. It's my first time using Azumarill so I don't know much about it, however I will continue to say I prefer Smack Down on Conkeldurr solely for the reason of pokemon with levitate that would otherwise take 3-4 turns to KO over 2 turns depending on the flow of battle up to that point. I'll switch out Scizor's Pursuit for Roost since Pursuit was just a placeholder in my mind for the sake of having 4 moves. Blissey is one of my best in battle because even with it's mediocre SpA it still 2 hits most pokemon, covers a lot of types, and with Serene Grace there's a greater chance of the moves' statuses being inflicted which can change the tide of battle greatly, however I do need to switch Grass Knot with Psychic.

Smack Down is not worth it. Fliers and Levitators can be smacked on the switch with Knock Off (to deny them of an item) or Ice Punch (which hits Fliers super effectively). Better yet, leave those to teammates. Or if you really hate Levitators, use Haxorus, as it has Mold Breaker to hit Levitators with Earthquake:
-Dragon Dance
-Outrage/Dragon Claw/Dual Chop
-Earthquake
-Poison Jab
Nature: Adamant
EVs: 36 HP/252 Atk/220 Spe
Item: Life Orb/Lum Berry
Ability: Mold Breaker

Never use offensive Blissey. Ever. Its Special Attack is mediocre for offensive purposes. Serene Grace abuse is also better left to Togekiss. If you want a better specially-based Normal attacker, use Exploud. Its Special Attack is higher, though it's still average by OU standards, but it has Boomburst, which is an insanely powerful STAB move to make up for it. The goal of Exploud is to spam Boomburst while it's on the field. Its coverage moves are meant to hit Rock and Steel Pokemon on the switch:
-Boomburst
-Overheat
-Focus Blast
-Flamethrower/Surf
Nature: Modest
EVs: 4 Def/252 SAtk/252 Spe
Item: Choice Specs
Ability: Scrappy

 

[Nah]

Never use offensive Blissey. Ever. Its Special Attack is mediocre for offensive purposes. Serene Grace abuse is also better left to Togekiss. If you want a better specially-based Normal attacker, use Exploud. Its Special Attack is higher, though it's still average by OU standards, but it has Boomburst, which is an insanely powerful STAB move to make up for it. The goal of Exploud is to spam Boomburst while it's on the field.

To add onto this, you're wasting Blissey's defensive potential. There's a reason why she's considered one of the best special walls in the game. That friggin' massive HP and good Sp.Defense, coupled with status recovery and healing, makes her nearly impossible to KO via special attacks. She's not meant for an offensive role due to her lowish Speed, so-so Sp.Attack, and physical fraility; just about any physical attacker can revenge kill her. There's other better special attackers to use.


Besides, having a healer/supporter on the team aint a bad thing.

 

[Mumzy]

If Your blissey is sucessful offensively then thats great. You have a tanky attacker on your team. to "Never use offensive Blissey. Ever." is a bit much. o_o The only suggestion I have is not to max out HP when it's already incredible in HP for an offensive pokemon and taking these EVs and putting where she's lacking which is Def by either adding half def half HP if not max Def.

Anyways, the obvious question is which steel Pokemon. As options you have Aggron and Scizor, which are good pokemon but two oposite ends of the scale. Addron is incredibly tanky and scizor is usually used to sweep. So what are you needing for your team?