5
You go to the three caves and catch them.
you can't catch it because you already beaten the legendary
You catch them with a ultra ball
no
you must die
you can start over
Yes quite a lot of them
there is no best spot
catch legendary Pokemon like giratina and heatran
uxie azelf dialga, mespirite, girantina and heetran
You'll have to have received it from a special event.
Not much. Pokemon diamond and Pokemon pearl have different Pokemon. for example, in pearl you can catch a glameow but not a cranidos and in diamond you can catch a cranidos but not a gleameow. And at the end of pearl you can catch Palkia the legendary and at the end of Diamond you can catch Diagla. But the games are basically the same. And there you go.....