you can only get it once you captured all 300 Pokemon and recorded them in the browser and once you did, go to Rand's house and you'll get a mission
It is Lugia.
In the room that contains Vulpix and the moving Bookcase that opens to the stairs.
Lugia
Not in Shadows of Almia. Just Guardian Signs.
Kyorgre isn't in pokemon ranger guardian signs. However, there is entei, rakou, suicune, lugia, mewtwo, ho-oh, and celebi.
You have to capture all 300 Pokemon then talk to Rand and he will give you a mission about Lugia. Blue eyes is there and she needs your help in the Undersea Cavern. There you will see and catch Lugia, then it will give you its Ranger Sign.
to go to the sea where you lost your styler and that's all i can say.
When not walking besides you during the game, while capturing he pops up on your screen when you have drawn enough loops to summon him/her, befriend more pokemon.
After you finish the game and beat all the quests and capture all the pokemon (except Lugia, of course) go to Rand's house.
latias is in Pokemon ranger signs.
complete your browser, then go to Rand's house for the last pokemon: the Lugia mission to save Blue Eyes!
Lugia. to acess it you need to catch the 300 other pokemon to catch. then a special mission to unlock it will be available. Enjoy!