Go to the moomoo farm on route 38 and feed the sick MILKTANK oran berries till he feels better. then talk to the girls surrounding MILKTANK and you should get a seal case and some seals.
You can find the Seal Case by feeding the Miltank Oran Berries at Route 39
5 or 6.
A Seal Case, after giving it ten Oran berries.
A fashion item that is contained in your case.
Y
No you do not need to help the miltank it is recommended though. You need to give it 7 oran berries then you will get a Seal Case and some seals. Which can customize the way your Pokemon enters the battle.
in a house near the ruins
talk to little boy in salaceon ruins. go to his house his mom gives u a seal case
no you can trade soulsilver pokemon to black
he is not in Pokemon soulsilver or Pokemon heartgold
U get it at the right of solaceon
POKEMON SOULSILVER come with a poke walker and the Soulsilver game