Get a Pokemon that is super effective against electric. Such as: Ghost, Psychic, Grass.
(I know that Ghost and Psychic arent exactly super effective, but they do pretty much enough damage that it is one hit KO.)
First you have to have surf and waterfall. then surf from sunnyshore city and get through victory road and your there.
Sunnyshore City.... xD
To turn on the power you must go to spear pillar which is on the top of mount coronet and save the 3 legendary Pokemon from the lakes then you must either catch or defeat dialga and the power will be turned back on.
In fact, there is no other way to Sunnyshore city other than that of going to Spear Pillar and coming back. Then, he is gone.
Oreburgh City
You can get one in sunnyshore city or underGround
there will be a man fishing in sunnyshore city
After you defeat Volkner in Sunnyshore City, a girl on the beach will gift it to you.
Remember the lake where azelf is the blue pokemon? well you go west of that lake then you go through the route and you will be in sunnyshore city
sunnyshore city
sunnyshore city is were you find it
as your going to sunnyshore city its in the grass north of the beach
In sunnyshore city in front of the lighthouse there is one on the ground
Sunnyshore City
In Sunnyshore city same as pearl/diamond.
sunnyshore city if you have palkia
at sunnyshore city