[quote=@Savo]
...[b][u]but permanently?[/u][/b] Kind of a stretch in my opinion... And it may make problems in the future. My two cents on this spiel.
[/quote]

[@AbysmalDemon]

I agree, particularly for Pokemon like Jirachi and Celebi where in the canon show and movies they are only available for a certain time frame. 

There are legionaries that don't really have a unique purpose in the wild like Phione, Latios, Latias, Shaymin (the...[u]Graditude[/u] pokemon?), Deoxys (doesn't have a clear purpose to the natural world), Heatran, Meloetta, Victini, Ho-Oh (The Victory Pokemon, could be an event Pokemon), Diance, Hoopa, Mew, and I think the 3 Legendary Dogs. These legendaries don't have any real consequences for taking them out of the wild.

Pokemon like Arceus, Palkia, Dialga, Cresselia, Darkrai, Rayquaza, Kyogre, Groudon would not only be over-powered but would have huge consequences from taking them out of the wild; thus they should remain "uncatchable" but can make an appearance for a short while.