Absolutely nothing.
Im not sure but hopefully something good, arrange the unkowns in alphabetical order in your box and oh don't forget the question mark, exclamation mark and the key unown.
You catch them.
All the Unkown are in Celestic Ruins
run around in every tomb for 1 hour
By catching all the unkowns after finishing the Pokemon league
26 unkowns
Tanoby Ruins
Capature All the unkowns. The located on the right of Solocaoen Town.
unkowns {pokemon}
nothingnothingOptional Answer:Well once you caught all Unknowns in Solaceon Town On the East the 2nd ledge go into the house talk to the boy he will give you the seals for the letters of your unkowns (Dont worry he wont take the unknowns)it will also help if you need a hippopotas (on Pokemon platinum)
It is located in Arlington National Cemetery in the United States.
World War II.