Omega Ruby / Alpha Sapphire Legendary Pokemon

Weather Trio

Groudon

Name: Groudon

Location: Cave of Origin, Maxie awakens it in Seafloor Cavern (Route 128)

Version Exclusive: Omega Ruby

Requirements: None

Level: 45

Moves: Lava Plume, Rest, Earthquake, Precipice Blades

Hold Item: Red Orb

Notes: Part of the main story line. If you knock it out on accident, it will respawn when you beat the Elite 4

Kyogre

Name: Kyogre

Location: Cave of Origin, Archie awakens it in Seafloor Cavern (Route 128)

Version Exclusive: Alpha Sapphire

Requirements: None

Level: 45

Moves: Body Slam, Aqua Ring, Ice Beam, Origin Pulse

Hold Item: Blue Orb

Notes: Part of the main story line. If you knock it out on accident, it will respawn when you beat the Elite 4

600px-384Rayquaza

Name: Rayquaza

Location: Sky Pillar

Version Exclusive: No

Requirements: Must capture to continue the story.

Level: 70

Moves:  *Fly, Dragon Pulse, Dragon Dance, Extreme Speed

Hold Item: None

Notes: *Zinnia teaches Rayquaza Dragon Ascent immediately after Rayquaza joins your team.

Lake Guardians

600px-480Uxie

Name: Uxie

Location:  Nameless Cave – near Sootopolis City when flying on Latios/Latias

Version Exclusive: No

Requirements: Pokemon with max happiness in your party

Level: 50

Moves: Yawn, Future Sight, Amnesia, Extrasensory

Hold Item: None

Notes: One member of the Lake Guardians shows up every 12 hours

600px-481Mesprit

Name: Mespirit

Location: Nameless Cave – near Sootopolis City when flying on Latios/Latias

Version Exclusive: No

Requirements: Pokemon with max happiness in your party

Level: 50

Moves: Lucky Chant, Future Sight, Charm, Extrasensory

Hold Item: None

Notes: One member of the Lake Guardians shows up every 12 hours

600px-482Azelf

Name: Azelf

Location: Nameless Cave – near Sootopolis City when flying on Latios/Latias

Version Exclusive: No

Requirements: Pokemon with max happiness in your party

Level: 50

Moves: Uproar, Future Sight, Nasty Plot, Extrasensory

Hold Item: None

Notes: One member of the Lake Guardians shows up every 12 hours

Swords of Justice

600px-640Virizion

Name: Virizion

Location: Pathless Plain – near Pacifidlog Town when flying on Latios/Latias

Version Exclusive: No

Requirements: None

Level: 50

Moves: Retaliate, Giga Drain, Sacred Sword, Swords Dance

Hold Item: None

Notes: Obtainable before Elite 4*One member of the Swords of Justice shows up every 12 hours

600px-639Terrakion

Name: Terrakion

Location: Pathless Plain – near Pacifidlog Town when flying on Latios/Latias

Version Exclusive: No

Requirements: None

Level: 50

Moves: Retaliate, Rock Slide, Sacred Sword, Swords Dance

Hold Item: None

Notes: Obtainable before Elite 4*One member of the Swords of Justice shows up every 12 hours

600px-638Cobalion

Name: Cobalion

Location: Pathless Plain – near Pacifidlog Town when flying on Latios/Latias

Version Exclusive: No

Requirements: None

Level: 50

Moves: Retaliate, Iron Head, Sacred Sword, Swords Dance

Hold Item: None

Notes: Obtainable before Elite 4*One member of the Swords of Justice shows up every 12 hours

Legendary Golems

Before you can access the three locations where the Regi’s are located, you you must have a Relicanth and Wailord as well as a Pokemon with Dig and Dive. On Route 134 you must take the correct path through the currents to the patch of water you can Dive in. Once below folow the path up to the Braille inscription and resurface. Go to the next inscription and use Dig. Make Relicanth the 1st of your party and Wailord the 6th, then read that inscription. Three earthquakes will trigger and open passages on each respective route.

600px-377Regirock

Name: Regirock

Location: Desert Ruins – Route 111

Version Exclusive: No

Requirements: (See above)Pokemon that knows Strength

Level: 40

Moves: Bulldoze, Curse, Ancient Power, Iron Defense

Hold Item: None

Notes: From the inscription go right twice, down twice and then use Strength

378Regice

Name: Regice

Location: Island Cave – Route 105

Version Exclusive: No

Requirements: (See above)

Level: 40

Moves: Bulldoze, Curse, Ancient Power, Amnesia

Hold Item: None

Notes:  Go to the next inscription and wait 2 minutes

600px-379Registeel

Name: Registeel

Location:  Ancient Tomb – Route 120

Version Exclusive: No

Requirements: (See above)Pokemon that knows Fly

Level: 40

Moves:  Bulldoze, Curse, Ancient Power, Iron Defense

Hold Item: None

Notes: Use Fly in middle of room

600px-486Regigigas

Name: Regigigas

Location: Island Cave

Version Exclusive: No

Requirements: Regirock, Regice and Registeel in party with Regice nicknamed and holding an ice item (CasteliaCone, Snowball or Never-Melt Ice)

Level: 50

Moves: Foresight, Revenge, Wide Guard, Zen Headbutt

Hold Item: None

Notes:  In the North-eastern house of Pacifidlog Town, a girl will tell you her grandfather’s stories. At random, she will tell you a part of the story about how to get Regigigas. This involves location and the other features. Take all the requirements above to the cave during the day and Regigigas will be there.

Tower Duo

600px-250Ho-Oh

Name: Ho-Oh

Location: Deck of the New Mauville

Version Exclusive: Omega Ruby

Requirements:  Need to obtain the scanner in New Mauville and give it to Captain Stern in Slateport who will give you the Clear Bell

Level: 50

Moves: Sunny Day, Fire Blast, Sacred Fire, Punishment

Hold Item:  Sacred Ash

Notes: Take the Bell to the deck of the New Mauville, the bell will resonate and a portal will appear

600px-249Lugia

Name: Lugia

Location: Underwater basement of the New Mauville

Version Exclusive: Alpha Sapphire

Requirements: Need to obtain the scanner in New Mauville and give it to Captain Stern in Slateport who will give you the Tidal Bell

Level: 50

Moves: Hydro Pump, Punishment, Aeroblast, Rain Dance

Hold Item: None

Notes: Take the Bell to the underwater basement of the New Mauville, the bell will resonate and a portal will appear

Legendary Beasts

600px-243Raikou

Name: Raikou

Location: Trackless Forest – near Rusboro City when flying on Latios/Latias

Version Exclusive: No

Requirements: Need Lugia or Ho-Oh in your party.

Level: 50

Moves: Spark, Reflect, Crunch, Thunder Fang

Hold Item: None

Notes: None

600px-244Entei

Name: Entei

Location: Trackless Forest – near Rusboro City when flying on Latios/Latias

Version Exclusive: No

Requirements: Need Lugia or Ho-Oh in your party.

Level: 50

Moves: Stomp, Flamethrower, Swagger, Fire Fang

Hold Item: None

Notes: None

600px-245Suicune

Name: Suicune

Location: Trackless Forest – near Rusboro City when flying on Latios/Latias

Version Exclusive: No

Requirements: Need Lugia or Ho-Oh in your party.

Level: 50

Moves: Aurora Beam, Mist, Mirror Coat, Ice Fang

Hold Item: None

Notes: None

Forces of Nature

600px-641Tornadus

Name: Tornadus

Location: Thundercloud – Fortree City when flying on Latios/Latias

Version Exclusive: Omega Ruby

Requirements: Need Castform in Party

Level: 50

Moves: Extrasensory, Agility, Air Slash, Crunch

Hold Item: None

Notes: None

600px-642Thundurus

Name: Thundurus

Location: Thundercloud – Fortree City when flying on Latios/Latias

Version Exclusive: Alpha Sapphire

Requirements: Need Castform in your party

Level: 50

Moves: Heal Block, Discharge, Agility, Crunch

Hold Item: None

Notes: None

600px-645Landorus

Name: Landorus

Location: Thundercloud – Fortree City when flying on Latios/Latias

Version Exclusive: No

Requirements: Need Tornadus and Thundurus in your party

Level: 50

Moves: Swords Dance, Earth Power, Rock Slide, Extrasensory

Hold Item: None

Notes: None

Creation Trio

600px-484Palkia

Name: Palkia

Location: South of Dewford Town when flying on Latios/Latias

Version Exclusive: Omega Ruby

Requirements: Azelf, Uxie and Mesprit in your party

Level: 50

Moves: Spacial Rend, Earth Power, Hydro Pump, Aura Sphere

Hold Item: None

Notes: None

600px-483Dialga

Name: Dialga

Location: South of Dewford Town when flying on Latios/Latias

Version Exclusive: Alpha Sapphire

Requirements: Azelf, Uxie and Mesprit in your party

Level: 50

Moves:  Earth Power, Aura Sphere, Roar of Time, Flash Cannon

Hold Item: None

Notes: None

600px-487Giratina-Altered

Name: Giratina

Location: South of Dewford Town when flying on Latios/Latias

Version Exclusive: No

Requirements:Dialga and Palkia in party

Level: 50

Moves: Shadow Force, Aura Sphere, Hex, Shadow Claw

Hold Item: None

Notes: None

Tao Trio

600px-643Reshiram

Name: Reshiram

Location: Fabled Cave – South-east of Mauville City while flying on Latios/Latias

Version Exclusive: Omega Ruby

Requirements: Level 100 Pokemon on your team

Level: 50

Moves: Fusion Flare, Dragon Breath, Extrasensory, Slash

Hold Item: None

Notes: None

600px-644Zekrom

Name: Zekrom

Location: Fabled Cave – South-east of Mauville City while flying on Latios/Latias

Version Exclusive: Alpha Sapphire

Requirements: Level 100 Pokemon on your team

Level: 50

Moves: Fusion Bolt, Dragon Breath, Zen Headbutt, Slash

Hold Item: None

Notes: None

600px-646Kyurem

Name: Kyurem

Location: Gnarled Den – Near Fallarbor Town while flying on Latios/Latias

Version Exclusive: No

Requirements:  Reshiram and Zekrom in your party

Level: 50

Moves:  Glaciate, Scary Face, Slash, Dragon Breath

Hold Item: None

Notes: If you use the dowsing machine, you can find DNA Splicers in the cave

 Other 

600px-485Heatran

Name: Heatran

Location: Scorched Slab

Version Exclusive: No

Requirements: Must have completed Groudon / Kyogre story

Level: 50

Moves:  Lava Plume, Scary Face, Metal Sound, Crunch

Hold Item: None

Notes: Located at the bottom of the cave.

600px-488Cresselia

Name: Cresselia

Location: Crescent Isle – South of Ever Grande City

Version Exclusive: No

Requirements: Random Daily Mirage Island

Level: 50

Moves: Mist, Aurora Beam, Future Sight, Slash

Hold Item: None

Notes:  Unlock method is still unknown.

Pokemon that cannot be captured in ORAS:
Articuno
Zapdos
Moltres
Mew
Mewtwo
Celebi
Jirachi
Darkrai
Shaymin
Manaphy
Phione
Arceus
Victini
Meloetta
Genesect
Xerneas
Yveltal
Zygarde

Source: http://www.serebii.net/omegarubyalphasapphire/legendary.shtml