You can't, you have to Migrate him over or trade.
yes
152 is rotom.
you can't
An event
You can't catch Mewtwo in-game in Pokemon Diamond.
It is impossable to get one in Pokemon diamond,but there might be one in Pokemon platinom...... hope that helped!
Golbat uses mean look in Pokemon pearl but i am not sure about Pokemon diamond and pearl.
Barboach. You can get it in the Safari Zone/ Great Marsh.
Route 212 http://bulbapedia.bulbagarden.net/wiki/TM11
You can find Latios on Pokemon Emerald, Ruby, and SoulSilver.
Latios is a non-breedable Pokemon,so no.
No legendary Pokemon even latios and latias can have eggs.