>>36556669>MewCatch the original 150 and it will roam the region
>CelebiGS Ball by Kurt after having at least one of each Pokeball (except limited or impossible balls like Master, Cherish, Safari, Dream or Park Balls) and beat the league or something
>JirachiFound after a festival in-game event
>DeoxysDelta Episode
>ManaphyObtain 100 flags and meet a Pokemon Ranger who will give you the egg
>DarkraiBring Creselia to an abandoned building and sleep in a specific bed
>ShayminBring the Gracidea to a flower expert and wait a day to have acces to a big flower path
>ArceusCatch the Creation Trio and bring it to a sanctuary
>VictinyHave a lot of victories in a battle facility or with other players and it will roam the region during daytime
>KeldeoBring the muskiteer trio to a castle or something and defeat a specific NPC
>MeloettaWin every contest in Master Rank and have access to a "Musical Master" or something
>GenesectTraded for a Fossil Pokemon to an evil team NPC during postgame
>DiancieHave at least 30 different Mega Stones and it will appear in a special cave
>HoopaHave a team full of transfered Pokemon and it will appear distorting the region like how the genies and Kyogre/Groudon changed the route's weather
>VolcanionHidden in a volcano or something similar to Heatran
>MagearnaFind an old toy maker aviable after main story
>MarshadowHave every type's Z-Crystal and it will roam the region during night
>ZeraoraHidden in a Power Plant, like Zapdos (don't really know anything about this guy)