You need to beat team galacic and or capture giratina
That'd be Volkner who remains the Gym Leader there.
you surf
you can get it before you get to sunnyshore city
sunnyshore city
U have to look him up at the light tower at the bottom right of sunnyshore city
After you beat team galactic's boss and catch/defeat giratina in the distortion world you will be able to get to sunnyshore city and after you beat the gym leader continue to the elite four.
by sunnyshore city
on the left of sunnyshore city. a fisherman has feebas
at the front of sunnyshore city
In A Grass Patch Close To Sunnyshore City.
first you you have to catch Giratina
=go to Youtube and go to Pokemon marriland.=