Pokedex for Uncatchable/one-catch?

[Avatarded]

I heard this game has weird rules about legendary pokemon where, if they exist, then they can only be caught and held by one player at a time. And, that in the final fight in black/white you always have the pokemon black legendary and fight the white legendary.

 

Is there a way to get the pokedex entries for these (virtually and literally) unobtainable pokemon for casual player?

 

Like, at bill's PC or something similar?

[Lightningvolt]

You can only catch Mewtwo, Rayquaza and Zekrom here

Some other legendaries can be seen with other NPCs but cannot be captured.

[Acarus]

all gen 4 uncatchable pkm will be added soon 

so your ''suggestion'' is quite useless