When you have the Third Shard talk to the larger member of the three shady characters encountered during the mission when Jeena was with you. This will give you the option to link to Spectrobes: Beyond The Portals to unlock Metallic Leopubar and Metallic Rygazelle.
If you have Spectrobes: Beyond the Portals for the Nintendo DS, you can get a metallic blue Rygazelle and metallic red Leopubar. They retain this color even after they evolve. They are not better than the regular colored ones, but they look very cool. They will be at LV.5 once you get them. Rygazelle is Water Property, and Leopuba is of the Fire Property. To obtain these secret Spectrobes, progress in the game until you beat the planet Menahat. Once you clear your mission there, talk to the tallest and most muscular of the 3 strangers that harassed you throughout the mission. He'll say he found a 'strange machine'. Talk to him again, follow the instructions the game gives you, and the Spectrobes will appear in the first 2 open slots in your Incubator. Again, there are no differences-besides color-between the metallics and the regulars.
When you have beaten Krux 'save' the game and then 'Continue' on the file you defeated him on. A silver Komainu will then be added to the first avalibe open space in your incubeator. His appearance will be similar to Leopuba and Rygazelle's but he will be shiny silver.
Press Up, Down, Left, Right, A at the 'Title' screen before you create a game save and a metalic Ryza and Leo will be added to your incubator when you start the game (this code will not work on a game that is in progress).