regis......HOW????

To get all three regis first have a relicanth and a walord. Then go to pacifidlog. Go the the current until you find a place to dive. Dive and then find a place with white on the rock, dive. Go all the way up then were there's writing use dig go up again have relicanth in front and walord in the back. Then go near dewford, the desert, and near lilycove. There you go all three regis.After you unlock the cave that the Regis is in before you fight Regis bring a Pokemon that can paralyze, and another that can confuse the Regis. Start by Paralyze Regis the confuse it. Then attack, (but use light attack or else you might wipe Regis out). Attack until Regis health bar is in the red and Regis is about to be wipe out. Then keep on throwing ultra balls at RegiS. IMPORTANT!!!!
Save before you fight Regis.
Hope this helps.

Well I this Q got me too until I swam Southwest of pacifidlog an I went into the current. Keep going west until you find a diving spot and use dive go down until you find writing on the wall. Get in front of it and use dive. Now go to the writing on the wall all the way up and use dig a hole should appear. When you go through the hole you go to the rock farthest up. Read or use dig on it.
In the one near lilycove use Fly in the middle of the room.A hole appears Registeel is in that one. In the desert tomb go to the writing and go down two steps then go over to your right 3 steps.a hole appears Regirock is in that one.Last and easiest to catch, regice. Go north of dewford until you see land the second time on your left. Use surf on the other side of it and go north. Read the writing and stand still in front of it.
This takes time if you use ultra balls so be patient

Note: to open the door, you need and wailord (evolves from wailmer @ lv.40), and a relicanth (bottom of the sea)

Ok this may take a few tries, but go to pacifilog town, and to the west there are strong currents. Keep going through the currents and you will find and space where you can dive. Dive down, and you will find a cave. Go in, and go to the back of the room. There should be a wall with brail writing on it. Now put relicanth on the the top of your list, and wailord at the bottom. Now "read" the brail. There should be rumbling and it will say something like, "it sounded like doors opened far away". note: there might be a first room b4 this one. If there is, walk to the center of the brail writing wall and use dig

Regirock=desert
Regice=ocean near dewford town
Registeel=near foretree city

In order to get to the room where regirock is, I believe you have go to the wall, walk 3 steps to the right, 2 steps down and use strengh. for regice, when you walk up and "read" the brail, all you have to do is wait about 2-3 minutes and it will open

For registeel, go to the center of the room and use fly

Hope this helps, and good luck