All you need to do is: talk to the man in artitian cave, and he will give you HM05 (flash). BUT, you can only use it after you have defeated the second gym leader. Once you have, go to the cave's basement, and as you can see it is scary dark. Go and teach the HM to a Pokemon, then press START, and then POKEMON, and go to the Pokemon that knows flash, press A on it, and press flash. As you will notice, the cave will light up. You can not light it up all the way as seen in the older generations of the Pokemon games... This can be used for all caves that are dark. Well I hope this message helped you loads. :)
The Pokemon you see do not go in your pokedex.
I See a Dark Stranger was created on 1946-07-04.
you have to see all Pokemon in the game (sinoh only) and the go to see rowan the profecer and oak will appear
You can see Garchomp from Cynhtia while you facing with her in the Pokemon league
you have to see all the Pokemon in sinnoh.
Because Ghost Pokemon can't see in the dark.
Use Flash.
you need to be in a dark spot.
See: Factories & Mines in the United Kingdom
after the Pokemon league,go too canalave city and talk to the sailor go to fullmoon island and go to cresselia (catching cresselia is the same as mespirit)pick up the lunar wing go back to canalave city go to the the closest house to the sailor and talk to the boy who's having nightmares because of darkrai (you need an action replay to capture darkrai). P.S You must see Pokemon movie Rise of darkrai.
When you Surf, you will see dark spots in the sea. You can then use Dive, and go underwater.
Actually, at Undella Bay, there is a place where you can go in the ocean, and in that place there is a dark spot in the water. Your pokemon has to know dive, but you can dive into that dark spot with dive. Once you do, you will see manaphy's castle, once you go in, you will have to fight it and capture it
go to sootopolis city, surf in the water,dive in the dark spot,go into the exit,as you can see the grasses,search Pokemon there,you can see:relicanth,clamperl,chinchou. rellicanth is rare so you can only see it sometimes.
you can see at mines view park.
See the Related Link.
Teach it to a Pokemon, then select the Pokemon you taught it to in the party and select Flash.
NO because it is dark it can not see you