The first picture was a commissioned piece by members of a pretty cool and friendly role-play forum. (link: http://gateway-2-rpg.4umer.net/ )
Second and the third are classworks for concept works.
The last two are from my story. First ones are the guardians with Lucetta (blonde girl), one of the main characters. The second ones are the Saints with their commander, Beatrix Santos Bellerose (white-haired girl), another main character. :)