Hows this team

[helldog]

Newly added Rotom and Forretress in this team. Now after looking at this team tell me whether it is a good idea to use Rotom over Gengar. Because I really did like Gengar but I needed an electric type in this team so had to pick Rotom. I also have 2 possible leads so that when I battle the same opponent, he cant predict which one Im using.

Forretress-Leftovers
Ability:Sturdy
Evs:252Hp/252Def/4SpDef
Nature:Relaxed
-Bug Bite
-Gyro Ball
-Rapid Spin
-Spikes
Role: Forretress is one of my possible lead and you'll see the other possible one right after this. Forretress acts as my defensive wall, spiker, and spinner. Set up spikes as much as you can before his HP goes low and then switch him back and send him out when he needs to spin. He can also use Bug bite or Gyro ball whenever he needs to attack. I dont need toxic spikes because I have a Breloom in this team who is just gonna try sporing everything he can. And I dont like using explosion because you dont know when he needs to rapid spin and the opponent spiker might spike again even if Forretress rapid spins it away once. Although rare, Forretress can switch into poison moves who try to kill my Breloom or a toxic.

Mamoswine-Choice Band
Ability:Snow Cloak
Evs:252Hp/252Atk/4Spd
Nature:Adamant
-Ice Shard
-Earthquake
-Stealth Rock
-Superpower
Role: Yes Mamoswine is my other possible lead. Depending on my mood and my predictability on what the opponent is going to send out first, I will switch around these 2 lead: Forretress and Mamoswine. Alright, so Mamoswine pretty much stealth rocks first. Then he switches right back in after since its choice banded and banding him is the only way he can possibly KO an intimidate Salamence with Ice shard. Mamoswine also acts as my dragon killer with ice shard. Dragons can be a real problem for this team so thats why I decided to use him for it. Mamoswine will also suck up electric attacks aimed at my Gyarados.

Houndoom-Life orb
Ability:Flash Fire
Evs:60Atk/196SpAtk/252Spd
Nature:Hasty
-Sucker Punch
-Overheat
-Reversal
-Solarbeam
Role: Houndoom is my mixed sweeper for this team. With this moveset, he pretty much covers everything either neutral or super effective. Although reversal only works when his HP is low but since he is fast, he probably will be able to use it effectively. Sucker punch for obvious reasons such as frail Gengars and Stamies. I picked overheat over fire blast because it has more accuracy and more power. And he probably needs to switch often because many sweepers can just KO him. Reversal for suprises on Blissey and Tyranitar and possibly Weavile. Solarbeam will only be used on slower ground/water/rock type switch ins and requires my smart predictability. Since most of the pokemon of those types are naturally slower than my Houndoom anyway, he probably will get to use solarbeam after one recharge. Also, another big thing that he does for me is to absorb fire attacks for my Breloom,Mamoswine,and Forretress. And psychic moves for my Breloom.

Gyarados-Leftovers
Ability:Intimidate
Evs:144Hp/92Atk/20Def/252SpDef
Nature:Careful
-Waterfall
-Bounce
-Dragon Dance
-Payback
Role: Gyarados is my specially defensive tank. Attack evs arent needed too much because he is going to DD anyway. Waterfall and Bounce for good coverage. Bounce is particularly for stab and good paralysis chance and free leftovers recovery while in the air. Payback for predicting Gengar and Starmie switch ins who try to kill me with a thunderbolt. Payback will double power even for switching pokemon, not just when Gyarados gets hit first by the way. Other than electric moves, this guy proves to be very bulky while being able to sweep at the same time. Also, he takes ground moves for my Houndoom.

Breloom-Toxic Orb
Ability:Poison Heal
Evs:156Hp/100Atk/252Spd
Nature:Jolly
-Spore
-Seed Bomb
-Focus Punch
-Stone edge
Role:Breloom is my annoyer/physical sweeper. He basicly puts the opponent to sleep and does damage as much as he can before the opponent wakes up. I dont like the sub and focus punch combo because it isnt necessary when the opponent is already asleep and it is highly unlikely to wake up in one turn. And sub just wastes one moveslot and takes away his sweeping capabilty. Breloom also abosrbs status moves for my pokemon.

Rotom(Heat)-Leftovers
Ability:Levitate
Evs:236Hp/130SpAtk/142SpDef or 142Def
Nature:Calm or Bold(142Def)
-Shadow Ball
-Thunder
-Overheat
-Pain split
Role: Rotom is my either defensive or special defensive(Which one is better?) wall/ sweeper. I can call him a wall since its got good recovery with pain split taking advantage of its low HP. And I can call him a sweeper too because its got nice stab and coverage and a good SpAtk stat. So basicly he is just there to take some couple hits, heal when he can and kill the opponents. And Im pretty sure not one pokemon is resistant to this set, everyone is either take neutral or super effective damage(Correct me if Im wrong) Another important key role of this guy is to support my team from ground/fighting/normal moves.

So how is this team? Is it okay to replace Rotom for Gengar?? Or should I put Gengar back on this team?

 

[Triangles]

Why use Thunder on Rotom? Tbolt outclasses it - it's far more accurate. You probably want something like a resttalk set on it with discharge and will-o and a physically bulky EV spread because it's gonna need to block spin quite a few times.
However, you might want to use a Choiced Rotom-H with Trick in the Fourth slot to mess up walls. Either way, don't use Thunder.

 

[helldog]

Yea

Yea I thought was thunderbolt was better too but since its special attack isnt as high, I thought of the more high powered thunder. But maybe I should change it.
Okay I'll try the physically bulky spread but what do you mean when spinblocking? The rapid spin isnt going to hit him anyway so what does defensively bulky have to do with spinblocking?

 

[Triangles]

Spinblockers generally should be bulky so that they can block spin multiple times and also so that they won't just fold to the attacks of offensive spinners, such as Starmie.

 

[Mulligan]

Might be a case of tl;dr but here we go.

You have a pretty good start going with the Gyarados/Breloom/Mamoswine core. I am still concerned, because you are actually quite weak to threats that are still common in the metagame. Although it is slightly less used, Life Orb Starmie is still common enough and can rip this team apart if Rotom-H is gone, despite the heavy special defense you have on Gyarados(Breloom won't save you either since it's taking 86% minimum from Ice Beam with your spread). Payback will do a ton on the switch-in, but it won't OHKO Starmie and only a fool would switch Gengar into a Gyarados(Rotom-A is the more likely scenario and it doesn't OHKO that either), Gyara is gonna take 65% + from a Thunderbolt while you take Starmie out and if SR is up, Gyara is done for the day. Forretress can be forced out by Heatran, a common lead, so you might not be able to spin them away. You have Sucker Punch on Houndoom, but the only situation where it's guaranteed to KO is if they switch their Starmie in on you(if you come in on them, they will think something is up), and there are many other ways to deal with Houndoom in OU. Tyranitar also has a field day with your current Rotom-H set and Dragon Dance sets with Stone Edge/Ice Punch continue to be popular. Although I hate what the set I'm about to suggest has done to DPP OU, I would recommend Scarf Rotom-W to start off on the right foot:

Hide

Rotom-W @ Choice Scarf
Trait: Levitate
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
-Trick
-Shadow Ball
-Thunderbolt
-Hydro Pump

With this set, you are at least able to check Starmie flat-out. It also gives some needed speed on the team since the priority moves you have are for very specific situations and can't be 100% relied on. Trick also gives you somewhat of a fighting chance against stall teams, which will murder this team just from looking at it since you designed the team with other offensive teams in mind. Tyranitar will also be kept at bay due to Hydro Pump and Rotom-W outspeeding even +1 Tyranitar. If you really want to keep it bulky, you can try a spread of 252 HP / 40 SpA / 216 Spe, without losing too much power.

I honestly do not see the value of Houndoom either. I like the surprise factor it gives, but it is a very situational set. Solarbeam can be seen a mile away and most, if not all, teams will pack a Grass resist to go to and immediately switch their Rock/Ground type out just before it hits. Houndoom needs to be extremely low for it to OHKO Blissey with Reversal, which is pretty easy to do, ironically, since Houndoom is affected by every entry hazard in the game and is weak to Stealth Rock. To put it in perspective, even Infernape lasts longer than Houndoom, which is pretty bad. I would try out a simple Substitute + 3 Attacks Heatran over Houndoom:

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Heatran (M) @ Leftovers
EVs: 40 Atk / 252 SAtk / 216 Spd
Naive Nature(+Spd, -SDef)
-Substitute
-Earth Power
-Fire Blast
-Explosion

The nature and EV's give Explosion more power and you still keep the surprise factor of taking Blissey out(I believe it OHKO's Blissey IIRC), since no one will expect an Explosion from behind the Sub. A Hidden Power is not needed IMO, since Breloom can cover Swampert pretty well and if you take the Rotom-W suggestion above, Gyarados would also be covered even better than it already is.

That's all I've got for now. There are other concerns, but I want to see if anyone else weighs in. This should be a good start though.