please help me decide the 6th pokemon for my first competitive team

[drago0202]

First I would like to thank everyone who helped me on the last thread I posted. With your help I was able to figure out 2 more pokemon for my team. thank you Nah, badsheep and platinumdude.so far my team is going to be
Salamence@Salemenite ( lead/ physical sweeper)
Adamant
4 hp/ 252 atk/ 252 speed
-dragon dance
-earthquake
-outrage (may switch to dragon claw)
-Double edge
Sylveon@ leftovers( cleric/ tank)
Bold
pixilate
252 hp/252 def/ 4 spd
-hyper voice
-protect
-wish
-heal bell
Metagross@Assault vest ( Offensive tank)
Adamant
clear body
252 hp/ 252 atk/4 spd
-meteor mash
-bullet punch
-hammer arm
-Thunder punch
Heatran@air balloon ( special hitter/wallbreaker)
Timid
4 hp/ 252 spatk/ 252 speed
- Heat wave/fire blast/ magma storm (notnsure which to pick
- flash cannon
-earth power
-protect
Grenija@focus sash ( mix sweeper)
Naive
protean
20 atk/236 spatk/252 speed
-surf
-ice beam
- dark pulse
-guk shot
????

So basicly like I said in my last thread I already have the first 3 pokemon listed and they arenworking very well together at the battle institute and battle maison. I'm really liking the dragon-steel core. After looking at the resistances and weakness of my team I would say ground attacks are biggest threat following by fighting and then electric. I plan on using air ballon on heatran (after I calture him and soft reset for ivs in spatk and speed). so for my 6th slot I'm thinking a physical sweeper I did look at Landorus and Heracross as options because of ground however I gain another team member than is weak to ice, does anyone have any good suggestions? All help is grealty appreciated!

 

[PlatinumDude]

Greninja needs at least 40 Attack EVs to guarantee the OHKO on Azumarill with Gunk Shot. It also needs Life Orb for the general power boost.

Protect isn't that useful on offensive Heatran. The last slot should go to Stealth Rock. Heat Wave is only useful in doubles, as it hits both targets; otherwise, it's outclassed by Fire Blast (for the general power and reliability) or Magma Storm (to trap targets).

Regular Metagross is overshadowed by its Mega counterpart because of the latter's better power and significantly better Speed. While Scizor is also a Steel Pokemon like Heatran, both have entirely different weaknesses; Scizor is still good even in its regular form:
-U-turn
-Bullet Punch
-Superpower
-Pursuit/Knock Off
Nature: Adamant
EVs: 248 HP/252 Atk/8 SDef
Item: Choice Band
Ability: Technician

As already mentioned by Nah in your last thread, Mega Salamence doesn't have much use for its Dragon STAB now since Aerilate Return/Double-Edge hits plenty of stuff really hard. The Fairy type also made it riskier to use Outrage, as Fairies can now block Outrage. Dragon Claw isn't a good option either, as it's not that strong. Here's a better take on Dragon Dance Mega Salamence; note this is a variation of Dragon Dance Salamence in past generations. It also needs a Naive/Jolly nature to outspeed as much things as possible pre- and post-Dragon Dance:
-Dragon Dance
-Return/Double-Edge
-Earthquake
-Fire Blast/Roost
Nature: Naive/Jolly
EVs: 252 Atk/4 SAtk/252 Spe
Item: Salamencite
Ability: Intimidate

 

[drago0202]

I was also thinking of maybe instead of heatran I could use volcarona because of its higher speed. Eventhough I agree that metagross is'nt nearly as good as its mega form he is still really good especially with assualt vest He becomes a tank. and for my 6th slot of thinking Terrakion. Inwould have 3 pokemon weak to fairy but grenija has protean.

I like your idea with the scizor though! Because like you said they have different weaknesses but would be good for the team. Hmm and then maybe I could go with Gengar for slot 6 Since I would no longer have the doulbe ghost/dark weakeness that metagross had!
Gengar@focus sash
Timid
4 hp/ 252 spatk/ 252 speed
-sludge bomb
-shadow ball
- Protect
thunderbolt or I could also go with a hex set and use heatran to set up.
for heatran should I then go with a bulkier set to replace metagross since he functioned as the teams main tank along with sylveon?

 

[PlatinumDude]

I like your idea with the scizor though! Because like you said they have different weaknesses but would be good for the team. Hmm and then maybe I could go with Gengar for slot 6 Since I would no longer have the doulbe ghost/dark weakeness that metagross had!
Gengar@focus sash
Timid
4 hp/ 252 spatk/ 252 speed
-sludge bomb
-shadow ball
- Protect
thunderbolt or I could also go with a hex set and use heatran to set up.
for heatran should I then go with a bulkier set to replace metagross since he functioned as the teams main tank along with sylveon?

Though Shadow Ball lets Gengar hit Steels neutrally, it's going to need Focus Blast in order to hit them super effectively:
-Shadow Ball
-Sludge Bomb/Sludge Wave
-Focus Blast
-Taunt/Destiny Bond
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Life Orb/Focus Sash

or
-Hex
-Taunt
-Will-o-Wisp
-Sludge Wave/Substitute
Nature: Timid
EVs: 4 Def/252 SAtk/252 Spe
Item: Black Sludge

or
-Substitute
-Shadow Ball
-Will-o-Wisp
-Taunt/Sludge Wave/Disable
Nature: Timid
EVs: 28 HP/148 SAtk/80 SDef/252 Spe
Item: Black Sludge

 

[drago0202]

Well I think that settles it. A team consiting of mega salamence, sylveon, scizor, heatran, grenija, and gengar is definitely balanced! Plus on top of that it still has that dragon-steel core that is doing wonders at the battle maison. I think I'm going to maybe invest more health into heatran to make him more of an offensive tank like Metagross was with a modest nature to hit as hrd as possible. Although his defense is not as high as metagross I think he will be better because of his typing and quadruple resistances. thank you so much platinumdude! If you wver need anything let me know!

 

[drago0202]

Also for heatran I'm thinking
heatran@Assualt vest
Modest
252 hp/252 spatk/4 spdef
-Heat wave/magma storm
-flash cannon
-earth power
-ancient power
I know that this is not a typcial set foe heatran but assualt vest turned metagross into a special tank and I'm thinking that it will convert Heatran into a special wall. I couldngo with a special defensive set like the one on smogon but it does1 hit nearly as hard. What do you think?

 

[PlatinumDude]

Also for heatran I'm thinking
heatran@Assualt vest
Modest
252 hp/252 spatk/4 spdef
-Heat wave/magma storm
-flash cannon
-earth power
-ancient power
I know that this is not a typcial set foe heatran but assualt vest turned metagross into a special tank and I'm thinking that it will convert Heatran into a special wall. I couldngo with a special defensive set like the one on smogon but it does1 hit nearly as hard. What do you think?

Not good at all. Assault Vest robs Heatran of the ability to use its support moves. Defensive Heatran isn't meant to hit hard; it's meant to spread status, get up Stealth Rock for the team and generally check/counter anything that troubles its teammates. There are better Pokemon to use Assault Vest on, like Azumarill and Conkeldurr, as these don't often run support moves. Refer to the Heatran sets below the defensive one for much, much, better offensive alternatives. This article should go into more detail about why Assault Vest isn't a good item on Heatran. Also, read what I said about Heat Wave; why are you still using it? Air Balloon is still the better item for offensive Heatran to temporarily avoid Ground moves. Offensive Heatran also uses a Timid nature and max Speed to outspeed walls. Since Heatran has good coverage in its offensive sets already, it can afford to use Stealth Rock in the last slot.