So, if you look at the photo for The Arena, you'll notice the sort of barnacle-like material and greenish shards protruding out of the ground - hive-like material(look at the bottom corners). Could this affirm multiple races we can fight, or is it simply terrain Bungie has put in?
Or might it be that the Prison of Elders have prisoners of all races?
-
I think it's located on the moon, maybe there's some sort of portal to get into there. Or maybe there's certain section you go through, each pertaining to a certain enemy. You walk though a portal to get th the next section to battle the next species of enemy