There are three other people in my class with Diamond and/or Pearl so we agreed to have a tag battle in which we would all participate. I've actually posted two sets of three Pokémon which I might use (I apologise if that's not allowed but I couldn't find a rule against it, and besides it's still six Pokémon altogether) in case there's something disastrously wrong with one of them, and it would be helpful to know which is better.
Our battle won't be restricted to a particular tier because we aren't all competitive battlers, but we agreed not to use Legendaries. I know nothing about their teams except their starter Pokémon (two Infernape and a Torterra), and for all I know they might not choose to use these. Also, our team pairings will be selected at random on the day of the battle, so it will be virtually impossible to build my team with their Pokémon in mind.
Since my tag battle team won't see particularly heavy use, I won't be using any TMs except those that are unlimited in the 3rd or 4th generation games. In other words, I will only use TMs that can be bought in shops or won at Game Corners or the Battle Tower.
Both (half-)teams are offensively oriented, but since they're designed for Double Battles most of the Pokémon are given fairly bulky EVs so that they can take a few extra hits.
Team 1
This team doesn't have any Fighting-type moves for Normal opponents, but that doesn't concern me too much since two of my friends have Infernape, so I'm likely to end up with some Fighting moves anyway. The team has only two special attacks, both on Mismagius, but again this problem can hopefully be solved by choosing some Special Attackers from my partner's Pokémon selection in case we have to face something with extremely high Defence.
Gyarados
Item: Life Orb
Ability: Intimidate
Nature: Adamant/Jolly
Moveset: Dragon Dance, Waterfall, Ice Fang, Stone Edge
EVs: 204HP, 96SA, 172SD, 36S
Gyarados has the Life Orb to boost its attacks, although I'm not sure how wise a decision this is considering that it could potentially have to take two hits per turn since it will have two opponents at once and it therefore might not last long. Its ability softens any physical blows, at least. Dragon Dance can boost its offensive stats as well, if necessary, and its attacks cover just over half of the types for super-effective damage.
Metagross
Item: Shuca Berry
Ability: Clear Body
Nature: Adamant
Moveset: Agility, Earthquake, Meteor Mash, ThunderPunch(?)
EVs: 152HP, 252A, 104S
Metagross is the main powerhouse of the team, and fortunately its ability prevents it from being hindered by Intimidate. Agility compensates for its mediocre Speed. Its attacks are powerful and have an advantage against 8 types. Metagross only learns ThunderPunch in Platinum, though, and since it's probably a while before that game comes out in the UK I might not be able to get this particular moveset in time. Also Metagross has high base EXP, so if I do decide to use this Pokémon I'll need a lot of patience and free time to train it up.
Mismagius
Item: Leftovers
Ability: Levitate
Nature: Timid
Moveset: Will-O-Wisp, Shadow Ball, Thunder Wave, Thunderbolt
EVs: 160HP, 128SA, 220S
I included Thunder Wave mostly in order to slow Infernape down, because it's a powerful, popular Pokémon which I know two of my friends have and Will-O-Wisp doesn't work on it. But I still want to keep Will-O-Wisp for other Pokémon with high Attack stats, as it should make it much easier to win. Shadow Ball is for STAB and Thunderbolt covers a couple of common types.
Team 2
This team is built under the assumption that my opponents will carry Electric moves (which is likely considering that Shinx is common early in the game). I know it's an old strategy to draw Electric moves with a Water Pokémon and then switch to Electivire, activating Motor Drive, but it's possible that my opponents won't know about it. And besides, I'm using Empoleon instead of the more conventional Gyarados. Empoleon and Gliscor cover up for a lot of each other's weaknesses so this team shouldn't have many problems defensively. Two of the three Pokémon in this team have Earthquake, so I might have to change this because the partner Pokémon won't necessarily be able to take the extra hits.
Empoleon
Item: Life Orb
Ability: Torrent
Nature: Modest
Moveset: Agility, Hydro Pump, Ice Beam, Grass Knot
EVs: 40HP, 252SA, 216S
Empoleon's Electric weakness is meant to draw Electric attacks and give Electivire an opportunity to use its Ability, but if my opponent sends out a Fighting-type instead I can switch to Gliscor. Hydro Pump isn't particularly accurate but it is a powerful STAB move and it won't hit Empoleon's partner Pokémon. Grass Knot is strong against Water-types but since it's a limited TM that no Pokémon can learn by levelling up, I might not be able to get it on Empoleon unless I can persuade a friend to breed from their Grass Knot Pokémon.
Electivire
Item: Expert Belt
Ability: Motor Drive
Nature: Adamant
Moveset: Thunderbolt, Ice Punch, Cross Chop, Earthquake
EVs: 252A, 80SA, 176S
Electivire is there for a pretty obvious purpose. Its attacks are super effective against most types and its item takes advantage of this. It has Thunderbolt to use if it gets Intimidated, which is likely to happen since Starly and Shinx are common early in the game so there's a good chance at least one of my friends has a Staraptor and/or Luxray in their team. No emphasis on defensive stats, though.
Gliscor
Item: Leftovers
Ability: Hyper Cutter
Nature: Impish
Moveset: Swords Dance, Roost, Earthquake, Stone Edge
EVs: 252HP, 40A, 216S
Gliscor is the most defensive Pokémon on this team, with Leftovers and Roost to restore its health. It doesn't need to worry about Intimidate thanks to Hyper Cutter so it has Swords Dance and a couple of physical attacks with good coverage to take advantage of its ability.
Completely random observation: both teams start with a blue, white and yellow Water-type and end with a red, purple and black Pokémon with yellow eyes.
Our battle won't be restricted to a particular tier because we aren't all competitive battlers, but we agreed not to use Legendaries. I know nothing about their teams except their starter Pokémon (two Infernape and a Torterra), and for all I know they might not choose to use these. Also, our team pairings will be selected at random on the day of the battle, so it will be virtually impossible to build my team with their Pokémon in mind.
Since my tag battle team won't see particularly heavy use, I won't be using any TMs except those that are unlimited in the 3rd or 4th generation games. In other words, I will only use TMs that can be bought in shops or won at Game Corners or the Battle Tower.
Both (half-)teams are offensively oriented, but since they're designed for Double Battles most of the Pokémon are given fairly bulky EVs so that they can take a few extra hits.
Team 1
This team doesn't have any Fighting-type moves for Normal opponents, but that doesn't concern me too much since two of my friends have Infernape, so I'm likely to end up with some Fighting moves anyway. The team has only two special attacks, both on Mismagius, but again this problem can hopefully be solved by choosing some Special Attackers from my partner's Pokémon selection in case we have to face something with extremely high Defence.
Gyarados
Item: Life Orb
Ability: Intimidate
Nature: Adamant/Jolly
Moveset: Dragon Dance, Waterfall, Ice Fang, Stone Edge
EVs: 204HP, 96SA, 172SD, 36S
Gyarados has the Life Orb to boost its attacks, although I'm not sure how wise a decision this is considering that it could potentially have to take two hits per turn since it will have two opponents at once and it therefore might not last long. Its ability softens any physical blows, at least. Dragon Dance can boost its offensive stats as well, if necessary, and its attacks cover just over half of the types for super-effective damage.
Metagross
Item: Shuca Berry
Ability: Clear Body
Nature: Adamant
Moveset: Agility, Earthquake, Meteor Mash, ThunderPunch(?)
EVs: 152HP, 252A, 104S
Metagross is the main powerhouse of the team, and fortunately its ability prevents it from being hindered by Intimidate. Agility compensates for its mediocre Speed. Its attacks are powerful and have an advantage against 8 types. Metagross only learns ThunderPunch in Platinum, though, and since it's probably a while before that game comes out in the UK I might not be able to get this particular moveset in time. Also Metagross has high base EXP, so if I do decide to use this Pokémon I'll need a lot of patience and free time to train it up.
Mismagius
Item: Leftovers
Ability: Levitate
Nature: Timid
Moveset: Will-O-Wisp, Shadow Ball, Thunder Wave, Thunderbolt
EVs: 160HP, 128SA, 220S
I included Thunder Wave mostly in order to slow Infernape down, because it's a powerful, popular Pokémon which I know two of my friends have and Will-O-Wisp doesn't work on it. But I still want to keep Will-O-Wisp for other Pokémon with high Attack stats, as it should make it much easier to win. Shadow Ball is for STAB and Thunderbolt covers a couple of common types.
Team 2
This team is built under the assumption that my opponents will carry Electric moves (which is likely considering that Shinx is common early in the game). I know it's an old strategy to draw Electric moves with a Water Pokémon and then switch to Electivire, activating Motor Drive, but it's possible that my opponents won't know about it. And besides, I'm using Empoleon instead of the more conventional Gyarados. Empoleon and Gliscor cover up for a lot of each other's weaknesses so this team shouldn't have many problems defensively. Two of the three Pokémon in this team have Earthquake, so I might have to change this because the partner Pokémon won't necessarily be able to take the extra hits.
Empoleon
Item: Life Orb
Ability: Torrent
Nature: Modest
Moveset: Agility, Hydro Pump, Ice Beam, Grass Knot
EVs: 40HP, 252SA, 216S
Empoleon's Electric weakness is meant to draw Electric attacks and give Electivire an opportunity to use its Ability, but if my opponent sends out a Fighting-type instead I can switch to Gliscor. Hydro Pump isn't particularly accurate but it is a powerful STAB move and it won't hit Empoleon's partner Pokémon. Grass Knot is strong against Water-types but since it's a limited TM that no Pokémon can learn by levelling up, I might not be able to get it on Empoleon unless I can persuade a friend to breed from their Grass Knot Pokémon.
Electivire
Item: Expert Belt
Ability: Motor Drive
Nature: Adamant
Moveset: Thunderbolt, Ice Punch, Cross Chop, Earthquake
EVs: 252A, 80SA, 176S
Electivire is there for a pretty obvious purpose. Its attacks are super effective against most types and its item takes advantage of this. It has Thunderbolt to use if it gets Intimidated, which is likely to happen since Starly and Shinx are common early in the game so there's a good chance at least one of my friends has a Staraptor and/or Luxray in their team. No emphasis on defensive stats, though.
Gliscor
Item: Leftovers
Ability: Hyper Cutter
Nature: Impish
Moveset: Swords Dance, Roost, Earthquake, Stone Edge
EVs: 252HP, 40A, 216S
Gliscor is the most defensive Pokémon on this team, with Leftovers and Roost to restore its health. It doesn't need to worry about Intimidate thanks to Hyper Cutter so it has Swords Dance and a couple of physical attacks with good coverage to take advantage of its ability.
Completely random observation: both teams start with a blue, white and yellow Water-type and end with a red, purple and black Pokémon with yellow eyes.
