Who is Tower Tycoon Palmer in Pokémon Diamond and Pearl?

Answer 1

In the Battle Tower at Battle Park, Tower Tycoon Palmer challenges you on your 21st Single battle and 49th Single battle. You have to beat 20 or 48 battles in a row to face him. You can only battle him in the Single battle mode though.

On 21st consecutive battle:

Milotic - Marvel Scale - Salac Berry (+ Speed a little bit)

Dragon Pulse

Hypnosis

Hydro Pump

Recover

Rhyperior - Lighningrod - Expert Belt (+ super-effective moves 20%)

Flamethrower

Ice Beam

Thunderbolt

Rock Wrecker

Dragonite - Inner Focus - Wide Lens (+ Accuracy 10%)

Stone Edge

Dragon Rush

Aqua Tail

Iron Tail

Use a Steel/Electric/Grass-type Pokémon that can't fall asleep, such as Empoleon or Magnezone. You don't need to satisfy all those requirements; you only need a Pokémon with enough Atk, Sp. Def, or Speed to KO Milotic before it KOs you, since Milotic has high Sp.Atk and Sp.Def.

Apparently, Rhyperior's purpose is to exploit any weakness that your opponent might have. You can use an item-stealing tactic, such as a Pokémon that knows Trick, to swap a Sticky Barb for its Expert Belt, or you can just use Thief if you intended for your Pokémon to not hold an item so it can use Thief. Rhyperior has very high Atk and Def but very low Sp. Atk, Sp. Def, and Speed, so one Surf should be enough to 1-hit KO it. Use a Pokémon resitant against all of its elemental moves, or just use a Pokémon that Fire, Ice, Thunder, and Rock are not super-effective against.

One Ice Beam from a decent Ice-type Pokémon should 1-hit KO Dragonite, but if Dragonite is faster, it can 1-hit KO before you can, due to its overall high stats, particularly Atk. Use a Pokémon with high Defense and can use Ice Beam; hopefully, since Dragonite is rather very strong, you have to either attack first and try to 1-hit KO Dragonite, or you can get hit first and hope to have at least 1 HP left to 1-hit KO Dragonite then.

On 49th consecutive battle:

Heatran - Flash Fire - BrightPowder (+ Evasion 10%)

Dark Pulse

Magma Storm

Flash Cannon

Explosion

Regigigas - Slow Start - Chople Berry (weakens foe's super-effective Fighting-type move)

Stone Edge

Ice Punch

Crush Grip

Brick Break

Cresselia - Levitate - Leftovers (at each turn's end, regain 1/16 of max HP)

Shadow Ball

Psychic

Calm Mind

Moonlight