Prestige Armor

Hey were do i get prestige armor and what is the core game bcuz on wikioidia it shows armor for prophicies , factions , and nightfall and the armor on core is called obsidian can i get that armor with prophicies?

When you hear the word "core" it generally means that whatever it is refering to is available in all three chapters. So, yes, you can get that armor with any of the 3 campaigns. How to do it:

1. Get enough materials and money (1.2 - 1.5 million gold's worth)
2. Go into the Fissure of Woe (accessible through Temple of Ages in Prophecies when your region has favor) with a knowledgable group
3. Do a few quests there to get the forgemaster to show up
4. Get your armor