How to get all legendary’s

Articuno: Roams Sinnoh reigon after getting national pokedex and talking to Professor Oak in Eterna City Lv. 50
Zapdos: Roams Sinnoh reigon after getting national pokedex and talking to Professor Oak in Eterna City Lv. 50
Moltres: Roams Sinnoh reigon after getting national pokedex and talking to Professor Oak in Eterna City Lv. 50
Mewtwo: Catch in FireRed/LeafGreen transfer to pal park or trade from Soulsilver or Heartgold
Mew: Get from Haleys farm in my Pokemon ranch in Pokemon diamond/Pearl then trade.
Raikou: : Catch in FireRed/LeafGreen transfer to pal park
Entei:: Catch in FireRed/LeafGreen transfer to pal park
Suicune:Catch in FireRed/LeafGreen transfer to pal park
Luiga: Get from FireRed/Leafgreen or trade from Soulsilver or Heartgold
Ho-Oh: Get from FireRed/Leafgreen or trade from Soulsilver or Heartgold
Regirock: Put level 100 Regigigas from giviway in party and go to cave on 228 or obtain in Ruby/Sapphire/Emerald 
Regice: Put level 100 Regigigas from giveaway in party and go to Mt. Coronet Upper 1f-3 or obtain in Ruby/Sapphire/Emerald 
Registeel: Put level 100 Regigigas from giveaway in party and go to Iron Island B3F 2 or obtain in Ruby/Sapphire/Emerald 
Latias; Transfer to palpark from Sapphire/Emerald, Trade with Heartgold
Latios: Transfer to palpark from Ruby/Emerald, Trade with Soulsilver
Kyrgre: Transfer to palpark from sapphire/Emerald, trade from Heartgold
Groudon: Transfer to palpark from Ruby/Emerald, Trade from Soulsilver
Rayquaza: Transfer to palpark from Ruby/Sapphire/Emerald, Trade from Soulsilver/Heartgold
Jirachi: Trade from Diamond/Pearl, Transfer to palpark from any GBA game
Deoxys: Trade from Diamond/Pearl, Transfer from Ruby/Sapphire/Emerald
Rotom: In TV in the old Chatue 8 PM to 4 AM
Uxie: Lake Acuity after you have been to Distortion World
Mesprit: Roams Sinnoh after seeing it at Lake Verity (must have been to distortion world)
Azelf: Lake Valor after you have been to Distortion World
Dialga: Spear Pillar/ Mt Coronet
Palkia: Spear Pillar/ Mt Coronet
Heatran: Spark Mountain very end. *must have talked to Buck in surviving area first
Regigigas: Snowpoint temple with all 3 regis in party
Girantina; Turnback cave or Distortion world
Cresselia: Goes around Sinnoh after you see it at Fullmoon island
Phione: Breed Manaphy with a ditto
Manaphy: Trade from Diamond/Pearl
Darkrai: Mystery gift in Diamond/Pearl, Trade
Shaymin: Mystery gift in Diamond/Pearl, Trade
Arceus: Mystery gift, Trade