'Shinies' are rare versions of the weapons you get from the new onslaught activity. There are sort of 2 versions: 1. The ones you get from shaxx in the hall of champions after completing weapon quests from arcite. These have a special ornament/appearence, have fixed rolls, and come pre masterworked. You can get one of each weapon this way. The perk rolls are not great, but not terrible. 2. Random shiny drops. These also have the special ornament and come pre masterworked but have random rolls and come with extra perks in columns three & four. These are the ones everybody wants.