Serperior can not learn Dragon Rush.
There is no TM for dragon rush. It can only be taught through leveling up or breeding
Chomp can't learn dragon dance, even not with breeding.
I say Flamethrower, to get rid of Ice types and more. You should have at least 2 dragon type moves, I suggest Draco Meteor and Dragon Claw. (TM Dragon Claw can be found in Mt. Coronet.) You should have Fly,too. You need someone who can fly you to other towns, plus more type coverage. If you use this moveset, Dragonite should have some EVs in Sp. Attack and Attack. Might want to get his speed in the 100s.
www.Pokemon.marriland.com. type in palkia scroll down and look at his moves and just to let you know palkia doesnt learn dragon pulse naturally but he can from a TM. and you can get TM dragon pulse at battle tower.
Serperior can not learn Dragon Rush.
Dratini, Dragonair, Dragonite, Lugia, Gible, Gabite, and Garchomp. Using breeding techniques, charmander, rhyhorn, aron, swablu, and bagon.
Garchomp learns the move Dragon Rush at lv.55
Dragonair does not learn Dragon Rush in Pokemon Leafgreen. However, it can learn the move in Pokemon Diamond, Pearl and Platinum at level 39.
Lugia is a Psychic/Flying type Pokémon, so no it is not a dragon but more like a bird.
LEVEL 85 ______________________________________ Learn Lugia Aeroblast .:.:.:.:.:.:.:.
In Pokémon SoulSilver, Lugia can learn the moves of Whirlwind, Weather Ball, Gust, Dragon Rush, Extrasensory, Rain Dance, Hydro Pump, Aeroblast, Punishment, Ancientpower, Safeguard, Recover, Future Sight, Natural Gift, Calm Mind and Sky Attack.
Lugia does not learn hydro cannon nor can learn hydro cannon.
between level 52 and 56
a gabite evolves into a garchomp they learn a realy good move called dragon rush.
Lugia can't learn psychic on its own, but you can teach it through TM29.
Crunch when it evolves and dragon rush at level 55 that's all I know...