You can read and know clearly the storyline of Pokemon Vega. This is a sequel to Pokemon Altair and Pokemon Sirius.
Three years ago, shortly after the crowning and subsequent retirement of Champion Brendan, Hoenn was battered by an enormous number of meteors. This disaster, known as the Hoenn Catastrophe, greatly transformed Hoenn’s landscape, turning much of the southern end into a barren wasteland and destroying the Battle Frontier, among other things. This also had a profound change on the wildlife, driving many species to extinction. More strangely, new species of Pokémon, known as Meteoric Pokémon, began appearing everywhere. At the forefront were three very powerful and evil Pokémon…
The story begins as you move into Littleroot Town, and are asked by Professor Birch to complete the Pokédex in order to document all the new species. You meet Birch’s niece (or nephew), April (or Gordon), as well as Billy, the little brother of the current League Champion, Wally. In addition, the Petalburg Gym Leader, Romero, has a little brother himself, who keeps crossing your path. His name is Mosmero, and he’s quite the strange one. Despite being an adult, he travels the region performing all kinds of pranks.
(The progression of the game mostly follows Ruby/Sapphire/Emerald, so lots of things will be omitted for brevity.)
You go on to defeat two Gym Leaders: Rustboro’s Rock-type Brock, the accomplished Pokémon Breeder, and the hot-headed Fighting-type Dewford leader, Mary. In Slateport City, you meet Team B.H. and their leader, Wallace. Their goal is to bring harmony to people and Pokémon through installing a competent leader to control everything. Unfortunately, their methods are highly illegal, and so they must be stopped.
After defeating the Poison-type businesswoman Barbara, Gym Leader of Mauville City, you head to Meteor Falls to stop Team B.H. from obtaining a meteorite called the Aura Stone. Although you fail, you meet Team W.H. and their leader, Steven. Their goal is to stop Team B.H. wherever they appear. At the peak of Mt. Chimney, Wallace reveals that his plan is to summon Rayquaza in order to capture it and rule as the leader of the world. He also mentions the name “Nemea”…
After stopping Team B.H. from using the Aura Stone to awaken something in the volcano, you defeat two more Gym Leaders: the silent Ice-type Alice of Lavaridge, and Petalburg’s quirky Romero, who uses Dark-types. As you head to eastern Hoenn, you encounter the Legendary Trainer, Brendan. He’s been traveling to different regions and defeating the Leagues there.
After stopping Team B.H. from stealing research data on the weather disturbances three years ago, you defeat the Fortree Gym’s Steel-type Leader, Mel. You then travel to Mt. Pyre, where Team B.H. has stolen the Blue Orb. You’re just in time to witness Steven himself steal the Red Orb for reasons unknown.
Deep inside the former Magma Hideout, where Team B.H. has set up shop, Wallace awakens Groudon using a combination of the Blue Orb and an artificial Pokémon of his team’s creation, named Ordina. He doesn’t care when Groudon flees, as this is part of his plan to recreate the conditions to summon Rayquaza.
Steven, meanwhile, reveals himself and his entire team to be evil all along, then snatches a submarine. He then flees to his hideout, the former Aqua Hideout, to modify the sub, and then off to Mossdeep. After you defeat the twin Gym Leaders of Mossdeep, Molly and Chaz, who use Fire- and Electric-types, respectively, Team W.H. attacks the Space Center. Team B.H.’s best and brightest scientists work there, and it’s where Ordina was developed and is currently stored. Despite teaming up with Brendan, you are unable to prevent Team W.H. from stealing Ordina.
Deep in the Seafloor Cavern, Steven uses Ordina and the Red Orb to awaken Kyogre. Steven and Wallace then race to the Sky Pillar to be the first to capture Rayquaza. Ordina reveals that it can speak, and laments its part in all this. It then rides away on Latios, who appears to know Ordina somehow.
In Sootopolis City, the two Legendary Pokémon fight once again. Brendan introduces you to his friend May, who goes with you to the Sky Pillar, but leaves once she becomes too concerned about the state of the city. While climbing the Sky Pillar, you defeat Wallace, and then defeat Steven just a few feet away from Rayquaza. He can no longer battle Rayquaza without conscious Pokémon, so he leaves to heal and try to catch Rayquaza on the way down.
Rayquaza awakens and disperses the battling Legendaries. At the same time, a change comes over Wallace and Steven. Apparently, their minds were being controlled by a Pokémon called Nemea, and Rayquaza’s descent reversed the effects. The two of them shamefully make their way to Mt. Pyre to return the Orbs.
You defeat the final Gym Leader in Sootopolis, the Dragon user Kagura, and go to challenge the League. After defeating the Grass-type Phil and the Psychic-type Athena, you find that Mosmero is the third Elite Four member. After taking down his Dark-types, and Elite Four Norman’s Normal-types, you battle the Champion, Wally, and win.
At this time you can choose to go to Mt. Pyre, where the keepers of the Orbs, Liza and Tate, will tell you a story. The three most powerful and evil of the Meteoric Pokémon were Lilapse, who could warp space, Ganimede, who could confuse the senses, and Nemea, who could control minds. The three of them caused all sorts of chaos, until one day, they suddenly disappeared.
After defeating the League, Mosmero calls with word of a new place to train. You take a ferry to Alto Mare, the mystical city of water, which is filled with canals. There, you meet Bianca, a young painter who takes care of injured Pokémon, and her grandfather Lorenzo, a gondolier. In addition, Alto Mare has an unofficial Gym. After collecting shiny stones for Bianca to paint a picture of, you fight the Ghost-type Gym Leader, Gina. She has taken in Ordina after Bianca apparently found it.
Afterwards, you find your way to a secret garden behind a fake wall, where Bianca plays with Latias and Latios. Gina allows you to befriend Ordina there, and Ordina’s horrible secret is finally revealed. It – or rather, she – was once a young girl from Pacifidlog Town. She was subjected to all kinds of experiments by Team B.H. that transformed her into a warped excuse for a Pokémon.
Mosmero then asks you to go investigate the Sphere Ruins, an enormous ruined city located below Alto Mare. After many, many ridiculous traps and puzzles, you find your way to the core, where a Pokémon named Asphere lies in wait.
At the end of your adventures in Alto Mare, you set off back to your original hometown, Porcelia Town in the Tohoak region, to reunite with your father, a man named Professor Holly. And thus begins your new adventure…
Other tidbits referenced in Vega or otherwise interesting:
- The entirety of Alto Mare is one huge reference to Pokémon Heroes, the Latias and Latios movie.
- The evil teams recycle their Admins – Team B.H.’s sole Admin is Tabitha, and Team W.H. has both Matt and Shelly.
- Wattson redesigned Mauville City to be more modern, although not to the extent of OR/AS. The new Gym Leader, Barbara, is his assistant.
- Mr. Briney’s new pet is a Surfing Pikachu named Peeka.
- The Alto Mare Cathedral contains a device called the Mirage System which allows battles with Mirage Pokémon.
- The remains of Team B.H. and W.H. were said to have fled to Kanto.
- In Verdanturf Town and elsewhere, people have started randomly adding the non-word “po” to their sentences. This is never explained.