The Shiny Latias Pokemon Website

Regirock:
To find the cave of the rock titan Regirock, you must have the Go-Goggles so that you may enter the desert. Once in the desert, go south to the bottom and enter the cave. In the back you will see the Braille in the back. Go to the back of the room and read it. The message translated reads "Left, Left, Down, Down. Then use Rock Smash." From the middle of the Braille on the wall move left, left, down, and down. Go with a Pokemon that knows Rock Smash and use it. The cave door will open. Save the game, then start the battle with Regirock. Note: Bring a lot of Ultra Balls.

Regice:
The cave of Regice is northwest of Dewford island. There is Braille in the back of the cave of Regice. The statement reads "Stay close to the wall. Run around the lap." You must run around the room once while staying close to the wall. Once you reach the middle of the Braille again, the door will open and the battle with the icy titan will begin when you go through the door and press A next to it.

Registeel:
To find the cave of Registeel, go to Lilycove City. Go west through the grass and trainers. When you reach the area of the Safari Zone, keep moving. You will reach a place with a girl. Just above her are stairs. You must go up. Go through the very tall grass and go up the stairs behind it. The cave will not be too far after the stairs. Once inside, read the Braille at the back of the room. It reads "Those who inherit our will, shine in the middle." The riddle means that you should go to the middle of the room and use Flash. The cave door will open. Be careful with Registeel. This Pokemon is more difficult than the others to capture. Try bringing a lot of Ultra Balls or prolong the battle as long as you can by freezing it or putting it to sleep. After many turns the Timer Ball will have gained a lot of strength, and it might work against the Registeel.

Go to the southeast part of Route 134 and dive into the water. It is difficult to get to due to the currents, and it is the only deep part of that route. You will find a cave. At a part of the cave, there are some Brail writing on the wall. At that point, float to the top of the water, where you will end up in a cavern. Go into the last room by going forward, use Dig, and in the next room you must do something strange. Put a Relicanth in the front of your party, and a Wailord at the last place. Walk to the top of the room and read the Brail . You will trigger an earthquake, which will unlock the Regis. You can fish up a Wailmer to evolve at level 40 at Route 122, and find a Relicanth outside Sootopolis in the underwater grass (rarely, but it is there).

To find Registeel, you can access a "volcano" in the southwest region of Route 120. Enter it, then move to the center of the room. Use Fly to find Registeel.

To find Regirock, fly to lavaridge, go down the mountain, and enter the desert (with the sand storms). In the southern part of the desert, you will find a cavern. Enter it, then walk up to the center tile at the top of the room. Go three steps down and two steps right. Use strength to open the passage to Regirock.

To find Regice, in Route 105, there is an island on the west side that has a mountain on it. Go there, enter, and stand in front of the tile. Press A, read it, press A again, and do not do anything else. The door will open after 5 min, and the last Regi is yours.