how do i get 2 sunyshore in pokemon diamond game???

If you beat snowpiont gym the events will lead you to canalve city. You have go to the library to the top level. You the professor their. Your here a eruption. From therethe three lakes (on your map). Go to the lake given to you then the other. After there events will lead up to the team galactic building. You have to save three legendary pokemon. From there you need to get to the top of mt. coronet. You have to stop cyris (it's been a long time science I battled him because I beat the game). After battiling dialga you can get to sunnyshore city.

You need to follow the story events up to the Spear Pillar first. Do you have the 7th Gym badge yet? If not, follow through the story events to Snowpoint City, and the Spear Pillar story will begin after, where you need to stop Team Plasma from summoning Dialga. You should catch it, and don't use your master ball, because it has a catch rate of 35. Or something like that. After that you can go to Sunnyshore.

you have to go to mt coronet to defeat cyrus and capture the dialga. then you go to sunyshore.

You play the game and he eventually moves