I'm going to say it outright: your team isn't very good. It still applies far too much pressure on Klefki to cover some of your team's crucial weaknesses, such as Dragon, Fairy, Flying, Dark and Ice. Without Klefki, you have absolutely no safe switch-ins to these types (Dark being an exception, though Hydreigon still shouldn't switch into Bisharp, Weavile etc.) As Klefki isn't overly bulky and has no reliable recovery, your team is incredibly easy to break. Even with Klefki, Pokemon such as Mega Charizard X can sweep you instantly if you allow them to set up. I am going to make some huge changes to your team to try and patch some of its major weaknesses, and provide move overall utility. I will also build it around Sticky Web.
Klefki
Klefki does not need Speed EVs, the only thing it gets out of them is a faster Dazzling Gleam which is rarely helpful and certainly not a worthy trade for extra bulk. Klefki performs best with 252 HP / 252 SDef / 4 Def, as this maximises its ability to against Pokemon like Mega Gardevoir, Keldeo, Lati@s whilst still having added bulk to take on Mega Pinsir, Weavile, etc. Dazzling Gleam is also weaker than Play Rough, which can also lower Attack, so use that instead, and change your nature to Careful for added bulk and lowered Special Attack now that you're not using the stat. Protect achieves very little for Klefki besides scouting for attacks and recovering 6% health with Leftovers, which makes it a situational move that likely won't be helpful. Instead you should use Thunder Wave, which cripples the Pokemon it switches into and therefore does the team a huge favour as many of those Pokemon threaten the rest of it. Running a dual screen set might also make sense, so Reflect might also help. If you do this, change your item to Light Clay to give the screens added longevity.
Hyderigon
This Pokemon is outclassed in OU. If you're in need of a special attack Dragon, you're looking at Latios or Latias, or their Mega forms. The set you're running doesn't do it too many favours, either; I'm not sure how you can expect Hydreigon to sweep when it's running 52 Speed EVs and has an unfortunate speed tier of base 98. Flamethrower + Earthquake is pointless they serve the same purpose. I recommend replacing Hydreigon for Latios, as it is faster, hits harder, has Defog and pairs well with another Pokemon I will add later. I will be replacing Mega Sceptile, so you may also consider using Mega Latios, though at the cost of the raw power that Life Orb provides. I recommend the following Latios set, which has Defog to support Talonflame and Galvantula and HP Fire to hit Ferrothorn, which you have trouble breaking past. You may also consider using Roost over HP Fire if you favour longevity. Latios pairs well with Sticky Web, as this can give it the edge in the many speed ties its base 110 Speed will cause.
Latios @ Life Orb
Ability: Levitate
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
- Draco Meteor
- Psyshock
- Hidden Power Fire
- Defog
Swampert
This is the worst set on your team. Basically nothing on the set works at all. Air Balloon is situational and less helpful than Leftovers. Swampert isn't weak to Ground, so it isn't helping much. Your mixed Swampert set doesn't make much sense as Swampert is weak on the special side and requires investment, weakening Earthquake. Sludge Wave fits better on your team that it would on others due to your Fairy weakness, but still isn't worth using. Outrage is an awful choice on anything that isn't Dragon type, as it hits only Dragon for super effective damage and locks Swampert into the attack, making it incredibly easy to set up on. Swampert itself simply isn't very helpful in OU, mostly because Rotom-W does its job ten times better than it does. Like Swampert, Rotom-W is a brilliant fit for your team, as your team has excellent resistance to its only weakness. I recommend a physically defensive set, as this can check many of the tier's threatening physical attackers that your team in particular is weak to, namely Azumarill, Weavile, Bisharp, Mega Medicham, Mega Metagross, etc. It is also a buffer against Volcanion which is a massive threat to the entire tier in general. It also offers burn support to wear down the opponent and shut down physical attackers. Its slow Volt Switch can be great to build momentum. Your team is well serviced on the special side, so you lose very little by going physically defensive.
Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 248 HP / 252 Def / 8 Spe
Bold Nature
- Volt Switch
- Hydro Pump
- Will-O-Wisp
- Pain Split
Galvantula
Though you are doubling up on Electric types with Rotom and Galvantula, Sticky Web seems integral to your team's design so I'll keep it around. Rotom and Galvantula don't double up on any weaknesses anyway, so it still fits in well defensively. In terms of changes, Focus Sash is generally better on lead Galvantula as it almost guarantees the Sticky Web. Life Orb can give it added punch and can catch some opponents off-guard if they aren't expecting such high offensive investment on Galvantula. You should change your ability to Compound Eyes and use Thunder over Thunderbolt for added power, and with decent reliability with 91% accuracy.
Talonflame
Offensive Talonflame fits in well on your team, as Rotom and Klefki combined already do what its specially defensive variant does. Offensive Talonflame is less common these days, so it also has a surprise factor. Talonflame can very very helpful as a late game cleaner, revenge killer and win condition, especially now that you have Defog support to remove its worst enemy, Stealth Rock. However, your set requires some changes.
Bulky Talonflame is a great Pokemon, but doesn't have much of a place in your team. Instead, run 252 Atk / 252 Spd / 4 Def with a Jolly nature for as much speed as possible and to have the faster priority attack against 252+ Weavile and others. Regardless of its set, it is imperative that Talonflame runs Roost as it allows it heal off recoil and Stealth Rock damage. As much as Taunt is a great move, it's better suited to defensive Talonflame and is less of a necessity than Roost.
Mega Sceptile
As alluded to, I recommend that you replace Mega Sceptile. You should get rid of the "I have no Grass type, so it's a good idea" mentality; instead, consider what offensive types are helpful to your team, and what weaknesses you have that the Pokemon could cover. Grass is good to hit Water type Pokemon that you otherwise can't hit for super effective damage, but that's about where it stops for Sceptile. Mega Sceptile is actually a bad fit for your team, as accentuates your Fairy, Ice, Dragon and Flying weaknesses and covers very little outside of bulky Water Pokemon that the rest of your team can't beat. You already have a Dragon type, too. Your set was also rather odd, without Leaf Storm and using Earthquake that isn't helpful against much except Heatran (though that is a large threat to your team). Also, if you like Leech Seed, you might as well run Giga Drain instead.
I recommend that you replace Mega Sceptile with Bisharp. Its Steel typing is great for your team as it provides resistance to several of the types your team is weak to. It can Pursuit trap threats like Latios and Gengar, use Sucker Punch for priority and use Defiant to discourage Defog, lest your opponent give you a free attack boost. Its weaknesses in Fighting, Ground and Fire are also covered well by your team. Several Bisharp sets can work well here, including Assault Vest, Black Glasses, Lum Berry and Life Orb. As you already have Swords Dance + priority in your team and Klefki already checks what AV Bisharp does, I think a standard Black Glasses Pursuit trapper is best. Life Orb is nice, but Bisharp has decent bulk and therefore can't freely throw away its HP as easily as other offensive Pokemon can.
Bisharp @ Black Glasses
Ability: Defiant
EVs: 252 Atk / 52 SpD / 204 Spe
Adamant Nature
- Knock Off
- Iron Head
- Sucker Punch
- Pursuit