Once you defeat the Dark Summoner at rank 30 or 40, there will be a disturbance in the town of Basalon. This disturbance is Shade, at rank 38. Like Dark Masko at Rank 20, Shade has fairly good magic defence, so you may have to use the same guard to defeat it, which will be Magiman (Or if you waited a bit longer and have the Spirit of Bombaman (which you can get from Dr. X laboratory once you defeated Bombaman), you can use him with all around stats, 120 magic and physical defence, 70 speed and rest magic attack (It should be approximatly 253 if used at rank 350.) for easy defeat) or Roroca, any dark guards with good magic defence stats and magic attack. However, if you wanted to buy him, you can't if you defeat him in Basalon Town. Instead you get a gem (Power or Nature), useful if you want to transform Dogi, Mycena, Dogia, Miki, Mickia, Trifish fire or water (Green) and more.
All of Shades moves, like Dark Masko's are dark.
Sleep Walk - 110
Blackhole - 115
Nightmare and Dark Sky - 120