use Dark type attacks like "Bite". It's really simple since's it's a Pyschic Pokemon
anywhere
No, you need to trade for it from Pokemon Pearl, Diamond, and Platinum.
The Legendary Pokemon in Diamond are Dialga, Azelf, Mesprit, and Uxie. That's all I know of.
If you have the marking map it will track mesprit, just don't fly.
walk out of the door!
There are only 3, Uxie, Mesprit, and Azelf.
no maybe if you hacked
No, you can't. To get it, you must trade from diamond, pearl, or platinum.
I think you go and catch it in it's cave.
dialga,palkia,mesprit,azelf,uxie,giratina,heatran,
The Pokemon that can be caught without special events, trading, or cheating in Pokemon diamond are: Uxie Mesprit Azelf Dialga Giratina Heatran
You can get Dialga Mesprit Uxie Azelf Giratina and if you somehow get regirock, regiice, and registeel on to diamond you can also get regigigas