use flash
swirly dust in caves.
victory road in side caves
By using the TM Flash
caves in dusck clouds
There is no legendary Pokemon in these caves, one only used to live there. It was possibly Keldeo.
Teach one of your pokemon 'flash' using a TM/HM
you use it in caves that have white fog and it gets rit of it
In Ruby, Sapphire, and Emerald; you can find them at the bottom of the sea and in caves. In Diamond, Pearl, and Platinum; You can find them on the ground, in caves, or Pokemon have them when you catch them or if they have the ability Pick Up. In HeartGold and SoulSilver; Pokemon in pokewalkers will randomly obtain them. You can also find them in caves and on the ground. In Black and White, they are in caves, on the ground, and Pokemon may have them.
you can find a Deino in the caves of Victory when you get 8 gym Badges
By attacking Pokemon in the grass, on water, in sand, caves or battling trainers. It's really simple.
You can't see it wild on Pokemon White but you can see it in Route 10, Route 11, Victory Road and Village Bridge on Pokemon White.
you don't see pokemon