Latias
Step 1. Get Slowpoke to change the weater at Cobalt Coast.
Step 2. Cloudy skies in the morn.
Step 3. Go to Cobalt Coast.
Step 4. Look over to faraway island.
Step 5. Answer correctly to obtain the card.

Answer: Glass

Latios
Step 1. Change weater at Cobalt to sunny.
Step 2. Cobalt is clear in the night.
Step 3. Look over to faraway island.
Step 4. Answer correctly to obtain a Latios Card.

Answer: (forgotten)