Introduction
Are you someone that play or have played Gen OU and have no idea what's going on this generation? Are you having a lot of problems adjusting to this generation and are confused to all the new changes? Well then, this guide was made for people like you. Most players have a hard time adjusting to this generation and end up giving up, simply because they just can't seem to grasp the new alterations of this generation. This guide will help you answer all your questions about the transition between Gen 4 OU to Gen 5 OU. It will make your experience with this new generation a lot more enjoyable. Good luck.
Gen 4 OU - The Transition
To begin with, this guide will help you understand the old Gen 4 OU Pokemon and their transition to Gen 5 OU. Every Pokemon will be listed here with a brief explanation of their old role in Gen 4 OU and their new role now in Gen 5 OU.
Heatran
Heatran was arguably the most dominant force in Gen 4 OU. Majority of the times, it was the most used Pokemon of the tier fighting alongside Scizor for #1. Heatran had many roles in Gen 4 OU. It was used as a great lead to handle other common leads and set up Stealth Rock. But unfortunately, the concept of a lead in Gen 5 OU has lost its meaning, simply because of the new Team Preview feature (which will be explained later). Heatran also served as a great revenge killer with a Choice Scarf set, being able to revenge kill common fast sweepers like Infernape, Gengar, Azelf, Lucario, etc. As well as serving as a powerhouse with Choice Specs as its item and a 130 Base Power SpAtk, easily OHKOing bulky Pokemon like Machamp, Rotom-A, Zapdos, etc. While posing a threat to any Pokemon that wishes to switch in safely. Heatran's other popular set was the offensive Life Orb sweeper set, which allowed it to sweep with ease, with its fearsome base 130 SpAtk boosted by 30% (from Life Orb). And Explosion allowing it to destroy almost any specially bulked Pokemon that tries to counter its Special Attacks, like Blissey. But with the transition to Gen 5, Heatran has lost it's #1 place on the usage statistics. Heatran's biggest loss in this generation is its ability to use Explosion. Heatran can no longer pose a threat to specially defensive Pokemon like Blissey with Explosion because of Explosion's downfall. Explosion no longer decreases the foe's Defense by 50%, meaning Explosion is only half as power this generation than last generation. This may upset you, but Heatran still plays a great role in the new metagame. With the new item Air Balloon, it can evade Ground-type attacks (but Air Balloon is a limited item, as once you've been attacked your Air Balloon pops). It is also still one of the best Stealth Rock supporters. As well as countering common threats like Ferrothorn, Scizor, Skarmory, and Jirachi. Heatran is also one of the best checks to a Drought team as it checks many opposing Chlorophyll abusers like Venusaur, Tangrowth, and Lilligant.
Jirachi
Jirachi has always had a great niche in every generation. In Generation 4, Jirachi had an infamous title, where it was disgraced by many players as a "luck-based" Pokemon. This was simply because of Jirachi's Serene Grace ability, doubling its chances of secondary effects. Iron Head's 60% flinch rate was really unbearable in Gen 4, where Heatran was the only hard counter to Jirachi. But with the advent of Gen 5, Jirachi has lost much of its recognition as a flinch haxing sweeper due to the many Steel-types and much faster threats. With rain up, Fire Punch won't be dealing much damage on Steel-types. While new bulky Water-types like Jellicent easily wall it and cripple it with Will-O-Wisp. Due to this, Jirachi has taken the role of being a specially defensive supporter this generation. With so many rampant Dragon-types, such as Latios and Latias, Jirachi has become the prime supporter to stop these threats. Along with Reuniclus and Gengar in OU, specially defensive Jirachi always finds its great niche in the metagame.
Dragonite
After Salamence got banned from Gen 4, Dragonite became the new powerhouse of the tier. After a Dragon Dance, it was able to rip holes trough the opposing team with a Lum Berry to prevent confusion or setting up on status. Or a Life Orb for unbearable power. With Choice Band, it's able to 2HKO even the bulkiest of Pokemon with Outrage, such as Scizor, Impish Gyarados, and Gliscor. Another role Dragonite served was the anti-lead role, being able to successfully take on common leads with its devastatingly power Draco Meteor. One thing to point out is its weakness to Stealth Rocks, which makes it lose 25% of its health every time it switches into the field, a good reason why Rapid Spin support is benificial. In 5th gen, it received a new ability, allowing it to outclass its brother, Salamence, which overshadowed when it was OU last gen. This new ability is called Multiscale, which halves the damage Dragonite receives from attacks, allowing it to set up and sweep much easier. Dragonite can also take advantage of permanent rain that Politoed brings to the field with moves like Hurricane and Thunder (both 100% accuracy in rain), and if you want you can use Surf, Waterfall, or Aqua Tail (all getting a 50% power boost in rain). Dragonite can also run a bulkier set coupled with entry hazards and abuse Dragon Tail to phaze and deal damage. Thunder Wave is also a great option for bulky phazing Dragonite.
Magnezone
What makes Magnezone stand out the most is its ability, Magnet Pull. This ability allows him to trap Steel-types such as Scizor, Skarmory, or Ferrothorn, set-up on them and then kill them off (or in Skarmory's case, killing him right of the bat as it could Whirlwind you away). Magnezone also has a great typing providing him of a lot of resistances. Magnezone also has access the move Explosion, the perfect move to get rid of those SkarmBliss combos in Gen 4. Magnezone could also use a Choice item such as Choice Scarf or Choice Specs, which allowed him to score some suprising kills. Also, access to Magnet Rise makes it easier to also set-up on Metagross, one of the most common leads. However, while Magnezone didn't receive much respect in the Gen 4 metagame, it is a commonly seen Pokemon in the 5th gen scenario. Mainly due to the fact that almost all teams have some kind of Steel-type Pokemon. Getting rid of the opponent's Ferrothorn or Skarmory is a valuable asset to any team. Its role hasn't changed much from Gen 4. Although it can't use Explosion anymore due to Explosion's power being degraded in half. It still easily traps Skarmory, Ferrothorn, Forretress, Jirachi and other common Steel-type Pokemon in Gen 5. It can serve as an essential utensil needed for a team that has trouble with Steel-type Pokemon, such as a team specializing with Dragon-types.
Bronzong
From its release in Diamond/Pearl, Bronzong has always been a very sturdy pokemon, a very bulky Pokemon. Bronzong has a great movepool to be an awesome supporter, getting access to Stealth Rocks, Reflect and Light Screen, also being able to Trick to cripple something, able to set up Trick Room if needed and then explode in your opponent's face. Its great typing, combined with Levitate makes it only weak to Fire-type moves, another reason why its so hard to take down. Unfortunately, it doesn't have any form of recovery outside of Rest, which means that it will die to repetitive hits. As far as gen 5 goes, Bronzong is a very useful pokemon not only because the aforementioned reasons, but because it is one of the best Pokemon to stop sandstorm abusers such as Excadrill or Landorus. With its immunity to Earthquake, resisting Rock Slide/Stone Edge and not taking much damage from X-Scissor or Return. It is also arguably the best counter to Gliscor with Hidden Power Ice and arguably the best Dragon Dance Dragonite and Salamence counter in the rain. In the rain, the power of Fire-type moves is weakened by 50%, meaning Bronzong has no weaknesses, easily being able to take a Fire Blast or Fire Punch.
Azelf, Aerodactyl, and other suicide leads
Back in Gen 4, Suicide leads were very commonly used. Their purpose was to either set up entry hazards, usually Stealth Rock, or to simply beat other leads. They were called suicide leads because they usually died in the first few turns of the battle, usually after they have fulfilled their purpose. Also, many of these suicide leads held Focus Sashes to ensure that they would survive long enough to serve their purpose. Azelf and Aerodactyl were two great suicide leads back in Gen 4. Azelf, in particular, was a very common lead, because of its many move options and great offensive and speed stats. Azelf could set up Stealth Rocks, Taunt opposing leads, set up Dual Screens, and even use Explosion to wipe out other Pokemon (because of Explosion's mechanics in Gen 4). Aerodactyl could do many of the same things that Azelf could. Aerodactyl could also set up Stealth Rocks and Taunt the opposing leads, in addition to just attacking them. What sets Aerodactyl apart from the rest is its base 130 speed, faster than nearly every other OU Pokemon. Apart from the lead spot, Azelf and Aerodactyl could run Life Orb based attacking sets to some effectiveness, however their true calling seemed to be suicide leads. With the introduction of Gen 5, the whole concept of leads 'flew out the window.' This was so because of the introduction of Team Preview, which lets you and your opponent choose the order of their teams before the start of the battle. Because of this, people were easily able to counter these suicide leads, thus they became less popular. Azelf and Aerodactyl, in Gen 5, are nowhere near as popular as they used to be, because their suicide lead sets simply don't work as well this generation. Their most common sets at this point have to be Life Orb based attacking sets.
Swampert
Swampert is, arguably, with the exception or Rotom-A, the OU Pokemon that more changed in the transition from Gen 4 to Gen 5, due to Team Preview, Ferrothorn, and the fact that Gastrodon and Quagsire, two Pokemon Swampert easily overshadowed in the past, received a very big upgrade. During Gen 4 OU, Swampert's main role was to keep common threats such as Tyranitar, Flygon, Kingdra among others in check. It also had a good matchup against most common leads, like Metagross, Infernape, Heatran (with the exception of Hidden Power Grass), Aerodactyl, and Gliscor, allowing it to easily lay down Stealth Rock. The lack of recovery was a huge letdown, but that could be solved to a certain degree by pairing it with Jirachi or Blissey, both of whom have acess to Wish, or, by using a RestTalk set. Swampert also has acess to Curse, but, due to its huge weakness to Grass-type moves, it wasn't used too much. However, in this new generation, Swampert's role is much different than before. While it's true it can still take hits well, Storm Drain's buff makes Gastrodon a better special wall, allowing it to keep Politoed, Starmie, Thundurus, and most Drizzle teams in check. Dream World gave Unaware to Quagsire, making it more efficient as a physical wall. With Curse and Unaware along with a priority recovery move (Recover), Quagsire easily outclasses Curse-sweeper Swampert. Though, Swampert is not totally outclassed in Gen 5. Swampert is still a decent Choice Band user, 2HKOing even stuff such as Conkeldurr with Waterfall and luring Ferrothorn, who is nicely taken down by Superpower. Unlike Choice Band Azumarill, Swampert gets access to STAB Earthquake and resistance to Electric-type moves. It also has good synergy with other rain abusers, such as Tornadus, Thundurus, and to an extent, most Water-type Pokemon that need a bulky Pokemon resistant to Electric-type moves.
